Cake, custard, raspberries and more cake.

Custard

3 large egg yolks

1/3 cup granulated sugar

3 tablespoon cornstarch

3/4 cup whole milk

3/4 cup heavy cream

1 vanilla bean, split and seeds scraped

1 tablespoon butter

Cake

1/2 cup (1 stick) unsalted butter, at room temperature, plus more for greasing the pan

1 3/4 cup (7 7/8 ounces) all-purpose flour

1 1/2 teaspoon baking powder

3/4 teaspoon kosher salt

3/4 cup packed light brown sugar

2 large eggs

1/4 cup whole milk

1 1/2 teaspoons pure vanilla extract

1 cup raspberries

Confectioners’ sugar, for serving

1. To prepare the custard, stir together the egg yolks, sugar, and cornstarch in a medium bowl until smooth. In a medium saucepan, bring the milk, heavy cream, and vanilla bean and seeds to a simmer over medium heat. Add a little bit of the warm milk mixture to the yolk mixture and whisk to combine. Repeat this process a few times until all of the milk mixture has been incorporated into the yolk mixture. Return the mixture to the pan.
2. Set a fine-mesh sieve over a large bowl. Cook over medium-low heat, stirring constantly and making sure to get the edges, until the mixture begins to thicken, 2 to 4 minutes. (It’s helpful to have both a spatula and a whisk handy while making the custard. Switch between the two.) Let it come up to a very slow boil and cook for 1 minute more. Strain the custard through the sieve into a clean bowl, and stir in the butter. Press plastic wrap onto the surface of the cream and refrigerate until cooled completely.
3. Preheat the oven to 325°F. Butter a 9-inch square baking pan. Line the pan with parchment leaving a 2-inch overhang on two sides.
4. To prepare the cake, stir the chilled custard to loosen it a bit. In a small bowl, whisk together the flour, baking powder, and salt. In a large bowl, with an electric mixer, beat the butter and brown sugar on medium speed until fluffy, 3 to 4 minutes. Beat in the eggs, one at time, scraping down the bowl in between. Beat in the flour mixture then milk and the vanilla extract. Fold in the 2/3’s of the raspberries. The batter will be thick.
5. Using an offset spatula, spread half of the cake batter evenly in the prepared pan. Top with the custard in dollops. Using the spatula, swirl the cake batter and the custard a few times to intersperse it. Top with dollops of the remaining cake batter and spread it out, covering the custard layer as best as you can. Top with the remaining raspberries.
6. Bake until a toothpick inserted into the center comes out with moist crumbs attached, about 1 hour. Cool slightly on a rack and then lift the cake out of the pan. Dust with confectioners’ sugar to serve.

I followed this recipe.