On the eve of holiday season, Tamar Adler—a lifelong dessert abstainer—takes a crash course in classical pastry. Can she conquer the fiendishly difficult mille-feuille?

It began in late summer, with a question “innocent as June,” as Emily Dickinson wrote. Subject: remaining things we’d like to change after we married. “More time on the water,” I said. Peter agreed. We would go sailing more, someday live by a river. Now him: “I was wondering if we might sometimes . . . have dessert?”

I hadn’t expected this. “Don’t we have dessert?” I asked. “Or, what do you mean?”

My husband-to-be explained gently that I seem to have a culinary blind spot. I believe meals end after salad and cheese. Sometimes I’ll offer fruit, never anything more. “Really?” I asked. Even at holidays, he added meaningfully. Restaurants too, he said. I ignore dessert menus so conclusively that looking at them isn’t fun.

It seemed to me he had to be exaggerating. I appealed to a larger sample set. A musician friend with whom I used to spend New Year’s: “Are you serious? You hate dessert. The last time you hosted, dessert was scotch.” A couple from North Carolina, fixtures at my table when they lived in New York: “There was one time you wrote us that if we wanted dessert we should bring our own. You spelled it with a single s, like desert.” It was the only typographical error they’d ever gotten from me. It was Freudian, they said.

I hadn’t read much Freud since college, but I did remember something about resistance—a sort of denial stemming from unaddressed trauma. Had I suppressed a memory of overeating pudding pie? Had a scarring encounter in the presence of an Easy-Bake Oven?

Or was my problem more practical? I ignored dessert simply because, despite four years in a professional kitchen, I never learned how to make it.

The sensible person here tries to bake a pie. Or a cake. Or cupcakes. But I have always had an unfortunate touch of hubris, an inexorable pull toward the steepest climb. To learn Spanish, I went to Salamanca, Spain, for the summer and enrolled not in Spanish class but in college-level art history taught in Spanish. The first time I skied, in the Alps above Innsbruck, I rode the funicular to the very top of the mountain. When I cook for someone I’m nervous about, my menu features temperamental leek soufflés.

So I feverishly wrote David Lebovitz, Parisian-pastry connoisseur and author of many cookbooks, including the inimitable trilogy Room for Dessert, Ripe for Dessert, andReady for Dessert, and asked what in the wide world of patisserie was most Everest-like. “Mille-feuille,” he wrote. Fiendishly demanding. “The technique alone is the ne plus ultra of pastry doughs. Unlike pâte brisée [no idea], pâte feuilletée requires great skill and a bit of daring.” I felt a flutter of desire. I checked, via old newspaper columns, with Craig Claiborne, the New York Times writer who loved complicated French food. He called the puff pastry of mille-feuille “the most difficult of pastries to make.” My aim was set.

Now to discover what, exactly, mille-feuille was. Compiled from various sources: Mille-feuille, or “a thousand leaves,” is pastry composed of three layers of pâte feuilletée (puff pastry) and two intervening layers of pastry cream or crème diplomate. The pâte feuilletée is made by efficiently layering butter into dough via rolling pin without the butter melting. The dough is folded over on itself again and again until you have 729 paper-thin layers of dough-encased butter, i.e., “leaves” in one flat rectangle. As the dough bakes, water in the butter turns to steam, causing expansion. The total number of flaky layers in the three tiers of a finished mille-feuille is, therefore, 2,187. But “deux mille cent quatre-vingt sept–feuille” lacks the limpid poetry of “1,000.”

I find a listing for a class called How to Make a Mille-Feuille, to be held at a bakery named Mille-feuille. I sign up.

The bakery is a pretty little place near Washington Square Park, shaded by plane trees. Inside, glass cases are filled with rows of riotously colorful macarons in flavors like praline, raspberry, lemon, salted caramel, pistachio, passion fruit. There are also eclairs, Saint-Honoré cakes, lemon and raspberry tarts, three flavors of mille-feuille, a glossy little cake called a Royal. I am struck first by how naive and splendid everything looks. And second, by a kind of cognitive dissonance: I know I’m here to cook, but I see nothing I associate with food.

Chef Olivier Dessyn possesses the precise phenotype of French pastry chef: a thin, high-boned face; big, deep eyes; shapely eyebrows; sharp hairline; well-defined nostrils that suggest large parts of the day spent anticipating what people are about to do wrong.

Here is how you make mille-feuille, as per my next three hours under his instruction.

Step 1: Make a dough of flour, butter, and water. Chill twelve hours. (Olivier did this ahead of time.)

Step 2: Whack a pound of butter around, then fold parchment paper into a perfectly square envelope. Somehow get butter into the envelope. Whack until butter precisely fills packet. (Olivier gives me a look I interpret as wondering why I can’t make a square. A square.)

Step 3: Take chilled dough and roll it into a square. Take whacked butter out of parchment and fold dough around it, until it’s entirely enveloped and . . . square. What I have written in my notes here is “I am not good at making squares.”

The next seven steps involve folding dough in thirds, then chilling it, rolling, folding, chilling again and again, until you have 729 feuilles in one coherent layer. You’re now through Step 10.

Steps 11–15: Bake the pâte feuilletée in several arduous stages. Finally, dust with confectioners’ sugar. Place in an extremely hot oven, but only for a moment. Repeat on second side. This is “caramelizing.”

Step 16: Make crème diplomate filling. Chill overnight.

Step 17: Put crème in a bag, and pipe between pastry. Quick math: This should all take about 40 hours.

While I have been pummeling flour and butter and scribbling notes, Olivier has baked a sheet of immaculate dough to a lacquered golden brown. He cuts it into neat rectangles and hands three—plus vanilla cream—to each student and gives careful instructions on piping, which we do, each producing a finished mille-feuille in which we can claim, if we are generous with ourselves, a small hand.

At 7:30 p.m., cycling home, pastry in knapsack, through the smog of downtown Manhattan, I notice that I smell rather wonderfully of butter and sugar. Once there, I serve the mille-feuille to Peter, confessing to the limits of my involvement. We note the silkiness of the diplomate, the fragility of the feuilletage. “It’s wonderful, love,” he says. “Just wait,” I promise. I’m on a path.

I remember seeing Chef Daniel Boulud make mille-feuille on the Today show once. I call the public-relations office of Daniel and explain that I’m a chef-cum-writer doing pastry-self-help-intervention therapy and need to train in their pastry kitchen. I’m working through something, I explain. Pastry chef Ghaya Oliveira agrees to take me on for two days. “I’ll bake you a mille-feuille,” I offer, “so you can gauge my skill level and help me improve.” She laughs and says, “Whatever you want.”

The next morning I panic. I’m convinced that everything in my kitchen tastes of garlic. All I can smell is garlic. What if I bring a garlic-flavored mille-feuille to Daniel? I briefly consider trying to pass off the remaining sliver of my mille-feuille from class as newly baked. But Olivier had insisted it be eaten immediately or discarded. “Mille-feuille is the cake of one day!” he’d shouted as we filed out of his bakery.

“Do it when it’s cold,” David Lebovitz had instructed. Our heat had been on. The kitchen thermostat reads 85 degrees, but it can’t be helped, so I roll my dough into a sort of kidney-bean shape, put it on a cookie sheet, use scissors to cut off what doesn’t fit, and slide it in the oven. It emerges, half an hour later, a bit buckled and mottled. I cut it into rectangles, though I can’t get their sides straight. My crème di­plomate, made during the baking, is impossibly lumpy. I do the best piping I can, step back to survey, then quickly put my first attempt at mille-feuille in a beautiful chestnut leaf–embossed Parisian cardboard box and head off.

Ghaya Oliveira, a tall, warm woman in chef’s whites with a charming Tunisian-French accent, greets me in Daniel’s vaulted dining room. She is so floury and compassionate that I feel reassured; the instant she sees my homely mille-feuille, she will hug me, then assign me to cracking eggs or counting cartons of cream—something with low stakes. I keep trying to hand it to her, to get this formality out of the way, but there are introductions, a tour. Then she’s called into a meeting with Chef Boulud. The box goes into a pastry refrigerator.

I’m put in the charge of an affable sous-chef, who asks me to select ripe figs for figues en robe. This is not a pastry skill. I do it well. Then to cut lime supremes—wedges without peel or pith; something any cook can do. My declarations of pastry ineptitude are thenceforth interpreted as false humility. I’m instructed to glaze the only 20 figues en robe in the restaurant, beautiful sweet purses of baked, dough-wrapped figs. I’m handed a little pot, a bucket of apricot glaze, and a paintbrush. I try to paint the figues but instead layer them with clumps and gelatinous drips of glaze. Ghaya emerges from her meeting just as I’m finishing clumping one of the last. She gasps. I relinquish my brush.

We get the box, open it. I unlock the first secret of pastry. Ghaya spends 20 minutes looking at it and begins analysis without tasting. About the slightly sunken top: “Your pastry is curved.” About the color: “It’s not caramelized all the way.” The borders are completely uneven. “You have to use a ruler to get them straight.” Where would I put a ruler? “Lay it right on top,” she says.

She takes a serrated knife to the pastry’s sides as she talks. In this sugary kitchen, taste and appearance are inextricable. Pastry, at least the classical sort I’m studying, must be beautiful. I have to admit my mille-feuille has begun to look smarter. Finally we taste. She notices lumps but says it tastes good. “The box is cute!” she pronounces. I leave her the box.

The next day I arrive at 10:00, don white jacket and houndstooth chef’s pants, and do a series of meticulous tasks under the watchful eye of a patient, serious pastry woman. I place tiny dots of fruit gel in the center of mousse in nickel-size molds. I’m shown how to fit rectangles of sucrée dough inside hollow metal dowels. I learn to use a doll-size spatula to remove lime-meringue strips from a cooling sheet.

Here is discovery two: What is made in a pastry kitchen occupies three dimensions in a way savory food doesn’t. It’s architecture. The original classical pastry was even more architectural; the field’s great nineteenth-century paterfamilias, Marie-Antoine Carême, was inspired by sketches of buildings, not meals. His pastry book Le Pâtissier Royal Parisien (1815) contained instructions for desserts shaped like fountains, temples, and pyramids. For the christening of Napoleon’s son, he devised a replica in sugar of a Venetian gondola, dyed brilliant colors, only partially edible. All the trimming and squaring, symmetry and rulers, preoccupation with densities, precise placements of filling, et cetera, is vital for the architecture of Ghaya’s Fleur de Café, Cerise Ébène, and Chocolate Coulant—all on her menu—to hold.

Because it is so exacting, I realize that getting good at even the most basic pastry, never mind the ne plus ultra, is likely to take years. (Ghaya tells me a story, meant to encourage but serving to depress, about spending ages learning how to hold a spoon correctly for scooping ice cream.) I will not learn what I need to achieve greatness on day two, and certainly not in time for the holidays. This somewhat dilutes the experience. The pastry cooks are kind. It is all interesting. The highlight, saying more about me than about the pastry kitchen, is that during dinner service I get to wear a tall, starched toque.

I despair briefly to my pen pal, Vogue photographer Eric Boman, who is completely on my side. He dislikes chocolate at any time but mid-afternoon and never has cake except for tea. Plus, he says, I should remind Peter that pastry chefs and regular chefs are different people for a reason. His Peter is the pastry chef in their house, and he likes to serve pruneaux au vin rouge or caramelized pears and sour cream “to people who are all disappointed they’re not getting chocolate cake.”

To be fair, my Peter didn’t ask me to learn to make dessert, just to eat it sometimes. I’ve gotten myself into a bind by having repeatedly sworn that I am on the verge of creating a magnificent, unrivaled mille-feuille, which will be the crown of our New Year’s table. So I call Olivier Dessyn and tell him I’ve been trying to learn everything but still need help to synthesize it all. In other words, would he please assist me in creating a pastry that conveys by way of grand finale that I have studied dessert’s meaning and forms and embrace it wholly.

I decide I want to make a cardamom-rosewater mille-feuille, whose cream filling will be both fragrant and pink. Ghaya had said great dessert must surprise, and I have decided rosewater and cardamom are unexpected. In Olivier’s kitchen we make dough and rosewater cream so speedily, all I do is hold whisks and spatulas in between phases and offer to wash mixing bowls. When we have the components—frivolous, rose-hued cream; extra cardamom for dusting; ice-cold pâte feuilletée—Olivier puts me in a taxi and wishes me bonne chance.

Because finishing involves only two more steps, the rolling and baking of pâte and the piping of pastry cream, I feel confident of success. I’d love to say I manage to cut my rather improved dough into neat rectangles. But there appear to be people even a ruler can’t help. The cream, though, is the most wonderful and exotic I’ve ever tasted, and I eat slivers of caramelized leaves and am shocked that a dough so buttery and fine has come out of my oven.

I assemble the mille-feuille with great flourish just as Peter arrives home. The instant he sits down, I set before him a slightly uneven but quite spectacular pastry. He takes a few bites, a bit palely. I descend into the exact intersection of desperation and rage. Peter calms me, though, by telling me firmly that it’s exquisite—which it is—but that he would really prefer to eat it after dinner. So when dinner (a Jerusalem-artichoke frittata, salad, baguette) is done, and it’s time, I replate it, on the gilt-edged Rosenthal china, and serve it to Peter, who smiles and offers me a fork to join him.

I reply immediately, without pause or thought, “Oh, no thank you. I’d prefer a peach.”