The French Pastry That’s Easy as Toast

The French creation consists of a slab of feathery brioche brushed with a citrus syrup; slathered in the sweet, fragrant almond cream frangipane; and topped with a smattering of sliced almonds. It’s baked until its top turns golden, the nuts crisp, and the bottom and edges caramelize, creating contrast with the pillowy interior.

While the treat is often compared to French toast, I think that sells it short. To me, bostock is more akin to an almond croissant, with layers of texture and toasty almond flavor and eaten out of hand. But there’s one major difference: Bostock is dead simple to make.

Start with a loaf of store-bought bread and whip up some easy toppings, and you’ll have breakfast, brunch, or a very special snack in no time.

Enriched with sugar and milk, brioche browns beautifully, and it’s also light and tender, which creates bostock’s plush bite. I bought an unsliced loaf of brioche so I could cut sturdy 1-inch slabs that could support the heft of the syrup, frangipane, and nuts. 

Bostock supposedly originated as a means of using up stale bread, and many recipes still call for stale. But I was dubious—while stale bread appears dry and primed to soak up bostock’s flavorful syrup, stale and dry bread aren’t actually the same thing. Stale bread’s moisture isn’t gone; rather, it’s trapped within the bread’s starch crystals.

When the bread is heated, that moisture is freed. This was bad news in the case of bostock: When I made a batch with stale brioche, the bread’s trapped moisture emerged in the oven, oversaturating the syrup-and-frangipane-soaked crumb and turning the bostock mushy. When I tried to pick up a slice, it collapsed. 

What I needed was bread that was actually dry, so I slid fresh slices of brioche into a low oven. After about 15 minutes, they were still yielding, but their surfaces were dry and firm enough to spread with the frangipane. Perfect.

The syrup in bostock flavors and moistens the bread, and it also encourages the bottoms of the slices to caramelize. Simple syrup is typically made by heating water and sugar on the stove, but you can also just whisk sugar with warm water and wait for it to dissolve. I could easily make the no-cook syrup as I waited for the brioche slices to dry, saving myself the trouble of turning on the stove. 

Orange flavor is often incorporated into bostock syrup, so I steeped grated zest in the syrup as the sugar dissolved for brightness and a hint of bitterness and then strained it out. I then stirred in a teaspoon of orange blossom water, another common addition, for elegant, floral notes and more citrusy complexity.

Frangipane is generally made with near-equal weights of ground almonds or almond flour, butter, sugar, and eggs. Versions of frangipane, from light and airy to dense and rich, appear in all sorts of pastries, and depending on the use, these ratios might shift. 

For my purposes, I wanted a thick, smooth paste, which luckily meant I could combine my ingredients by hand and didn’t need to haul out the stand mixer or food processor to incorporate air.

Using the traditional ratios as a guide, I worked softened butter and sugar together and then added a couple eggs and almond flour, along with some salt and almond extract (extract is made with bitter almonds, so it brings a different expression of almond flavor than the nuts do; for more information, see page 30). But the resulting frangipane was so runny that it dripped off the sides of the brioche.

Eliminating one of the two eggs got me closer to the dense texture I was looking for, but I still wanted a bit more body. Adding a tablespoon of all-purpose flour, as many bakers do for thicker frangipanes, did the trick—because it contains more starch than almond flour, all-purpose flour is more absorbent, so it efficiently bound up the extra moisture and created a velvety yet spreadable cream.

After brushing the dried bread slices with the orange-scented syrup, I spread ¼ cup of frangipane on top of each slice, enough cream to sink your teeth into. Then I arranged a thin layer of sliced almonds over the top of each slice, both to add toasty crunch after baking and to ensure that the frangipane, which puffs slightly in the oven, would rise evenly.

I resisted the temptation to add more almonds to each slice—it’s key that the nuts form a single layer so they brown evenly. 

After drying the bread, I had cranked up the oven to bake the bostock. After about 20 minutes of baking, I pulled the pastries from the oven and placed them on a wire rack so they could firm and crisp up before I dusted them with powdered sugar.

The bostock was tender and moist, with a crisp top, a slightly chewy middle, and a caramelly, browned bottom. I loved the way the frangipane and toasted almonds showed off the nut’s range, but I also started dreaming up other toppings. Switch it up by adding fresh berries or chocolate chips, and you’ll never tire of this marvelously simple treat.