Hello Ontario strawberry season, my unofficial start to summer! Every June I start stalking the websites of our local farms waiting for the announcements that The Strawberries Are Here. I love picking all types of fruit, but strawberries might be my favorite. Pulling back the leaves to find those extra-ripe-and-red ones hiding in the middle of the plants, keeping an eye on the kids to make sure they aren’t sampling more than is socially acceptable — strawberry picking is an experience I relish every year.
One of my must-bakes every strawberry season is a fraisier (cc: this berry basil fraisier from the archives and a strawberry elderflower version in my book), but this year I wanted to work on some other desserts that would showcase the beauty of in-season strawberries. When working with such perfectly ripe fruit, my motto is always “Less is more!” If your strawberries are perfectly candy-sweet, I think it’s a shame to cook them or overshadow their flavor with any strong flavoring.* Enter: this fresh strawberry sable breton tart with vanilla bean mousse.
*If you’re picking pounds and pounds, ok, I get it. Just promise me you’ll enjoy at least a portion of them as unadulturated as possible!
Sablé breton, or French-style shortbread, straddles the line between cake and cookie, thanks to richness from egg yolks and butter and lift from baking powder. It makes a wonderful tart base; it’s sturdy and actually holds up fairly well to refrigeration. (Once topped it does soften with time, but doesn’t get as soggy as some other tart crusts do.) I roll out my dough, cut out the pastry with a cake ring and bake the base directly in the ring for the cleanest look and easiest unmolding. However, you can also press the dough evenly into a cake ring or parchment-lined cake pan.
With this amount of pastry, I got one 6″ tart plus three 3.5″ tartlets. Alternatively, you could use all the dough to make one 8″ tart, or bake off extra dough as cookies. One last thing — for the best-tasting sablé breton, I stick with tradition and use European style (84% butterfat) cultured salted butter. If you don’t have salted butter on hand, increase the salt to 1/4 tsp.
Vanilla Bean Mousse
For the creamy element, I borrowed a page from the ever-genius Bravetart with a egg-white vanilla bean mousse. The mousse starts with what is essentially a pastry cream made with just egg whites. (Conveniently, you’ll need the exact amount of egg whites leftover from the sablé breton. Recipe development score!) This may seem odd, as classic pastry creams usually rely on egg yolks for flavor and richness. However, Stella Parks notes in her book that egg whites can thicken pastry cream just as well as yolks. The resulting custard just has a more neutral, clean flavor — perfect for letting infusions take center stage. Here we’re sticking with classic vanilla. It’s definitely worth breaking out a real bean here — your mousse (and tasters) will thank you! You’ll use half the seeds for the pastry and the rest plus the pod for the mousse.
All the beautiful strawberries
Base, check; cream, check — the only thing left is to pack the tart full of as much fresh strawberry goodness as possible. I fill the center with lots of finely diced strawberries mixed with a touch of jam, then pile the top with the prettiest berries I have — I like to keep the stems on a few of them just for aesthetics. You can brush the decorative berries with some warmed apricot jam if you want a little shine or if you’re storing the tart for more than a couple hours (this will keep the berries for drying out).
Light, elegant, and fresh, this strawberry sablé breton tart with vanilla bean mousse has joined the fraisier as one of those desserts I’ll anticipate every strawberry season. I’m also dreaming up some other fruit-mousse combos — cherry and chocolate? Peach and brown sugar? Lychee and coconut? Stay tuned!
Fresh Strawberry Sablé Breton Tart with Vanilla Bean Mousse
Makes one 6″ tart plus a few small tartlets, or one 8″ tart
For the vanilla bean mousse:
- 170g whole milk
- 113g heavy cream (35% milk fat)
- Seeds of 1/2 vanilla bean, plus pod
- 65g granulated sugar
- 1/4 tsp kosher salt
- 17g cornstarch
- 60g (from about 2 large eggs) egg whites (reserve yolks for sable breton)
- 14g unsalted butter
- 1/2 tsp vanilla extract
- 85g heavy cream, cold
For the sablé breton base:
- 125g all-purpose flour
- 5g (1 1/4 tsp) baking powder
- 40g egg yolks (from about 2 large eggs), at room temperature
- 80g granulated sugar
- 1/8 tsp fine sea salt (increase to 1/4 tsp if using unsalted butter)
- Seeds of 1/2 a vanilla bean (reserve remaining seeds and pod for mousse)
- 85g salted European-style butter, very soft
For the fresh strawberry filling:
- 150g fresh strawberries, stemmed and finely diced
- 40g (2 Tbsp) seedless strawberry preserves (or other complementary flavour)
- Fresh strawberries
- 1-2 Tbsp apricot preserves (optional)
Make the vanilla mousse:
Set a fine-mesh strainer over a medium heat-safe bowl or container.
In a medium saucepan, combine the milk and 113g heavy cream and bring to a simmer over medium heat. Meanwhile, place the sugar in a medium bowl and rub in the vanilla bean seeds. Add the empty vanilla bean pod to the heated dairy; then remove from heat, cover, and infuse for 30 minutes (or up to 1 day, in the refrigerator).
Remove the vanilla bean pod and scrape any pulp back into the saucepan. Bring dairy back to a simmer over medium heat. Meanwhile, whisk the salt and cornstarch into the vanilla-sugar until well combined. Whisk in the egg whites.
Once the dairy reaches a simmer, remove from heat. Pour about half the dairy in a slow, steady stream into the egg white mixture, whisking constantly to avoid cooking the eggs. Scrape the warmed egg white mixture back into the saucepan. Cook over medium heat, whisking constantly, until the custard thickens and starts to bubble. Once bubbles appear, continue whisking the custard on the heat for one full minute to cook out any starchiness. Strain into the prepared container. Whisk in the butter and vanilla extract. Press a piece of plastic wrap directly against the surface of the custard and cover. Refrigerate until cold, at least 4 hours (or up to a week).
Once the base is chilled, whip the remaining 85g heavy cream to medium peaks. Stir the custard base until smooth; then gently fold in the whipped cream until well combined. Transfer mousse to a piping bag fitted with a large round or open star tip for at least an hour before assembling tarts. (Mousse can be prepared up to 5 days in advance.)
Make the sablé breton base:
In a small bowl, whisk together the flour and baking powder. Set aside.
In the bowl of a stand mixer fitted with the whisk attachment (or using an electric hand mixer), combine the egg yolks, sugar, and vanilla bean seeds. Whisk on medium-high speed until pale and thickened, 2-3 minutes. With the mixer still running, add the butter a tablespoon at a time. Mix until well combined. Scrape down the sides of the bowl. Add the dry ingredients and fold in with a flexible spatula just until no streaks of flour remain.
Scrape the dough onto a piece of parchment or silicone mat and place a piece of plastic wrap on top. Roll out the dough into a round between 1/4″ and 1/2″ inch thick, peeling off and replacing the plastic wrap every few rolls to avoid getting creases in the dough. Transfer the dough (with the plastic wrap on top) to a sheet pan and refrigerate until firm, at least 1 hour (or up to 5 days).
When ready to bake, preheat the oven to 350F with a rack in the middle. Flip the dough over (the plastic will now be on the bottom) and peel off the parchment or silicone mat. Then replace the parchment and re-invert the dough. (This step ensures the dough isn’t stuck to the parchment or silicone.) Transfer the parchment with the dough on it back to the baking sheet and remove the plastic wrap. Use a 6″ cake ring to punch out a circle of dough. Remove the excess dough around the outside of the ring, but keep the cut round inside the ring. Use a fork to poke the dough in the ring all over. Press the remaining dough into tartlet molds or refrigerate/freeze for later use.
Bake the sablé breton until golden, about 25-30 minutes for the 6″ round (about 20 minutes for smaller tartlets). Let cool completely in the molds before assembling.
Assemble the tart:
When ready to assemble the tart, mix together the diced strawberries and jam. Spread the filling on the tart base, leaving about a 1″ border. Pipe the mousse around the edge and over the filling. Decorate with fresh strawberries as desired (you can brush the berries with warmed apricot jam for a little shine). Refrigerate until ready to serve. Tart is best enjoyed the day it’s assembled. Store leftovers in an airtight container for up to 3 days. The pastry will soften with time, though it becomes more cakelike rather than soggy — not a bad thing at all!