Ingredients
Unsalted butter, for greasing the pan
12 oz [340 g / about 2 ½ cups] fresh blackberries
1 ½ cups [190 g / 6 ¾ oz] all-purpose flour:
(I used whole-wheat pastry flour in the same weight)
1 ½ tsp baking powder
½ tsp kosher salt
4 large eggs, separated
¾ cup [150 g / 5 ¼ ounces] sugar
⅓ cup + ¾ cup [240 ml / 1 cup total] whole milk
1 vanilla bean, split and seeds scraped
¾ cup [240 ml / 240 g] sweetened condensed milk
¾ cup [180 ml] evaporated milk
¾ cup [180 ml] heavy cream
1 tsp vanilla extract
Instructions
- Preheat the oven to 350F [180C]. Butter the bottom of an 8-inch square baking pan.
- Cut 6 oz [170 g] of blackberries in half lengthwise and set aside.
- In a small bowl, whisk together the flour, baking powder, and salt. In a large bowl, with an electric mixer, beat the egg yolks and 1/2 cup [100 g] of the sugar on medium speed until pale and thick, 3 to 4 minutes. Beat in 1/3 cup [80 ml] of the whole milk and the vanilla seeds. Beat in the flour mixture, just until combined.
- In a large bowl, with clean beaters, whip the egg whites until foamy and the yellowish hue has disappeared, about 1 minute. Slowly add the remaining 1/4 cup [50 g] sugar while beating and continue to beat the mixture until you have shiny, medium-stiff peaks, about 2 minutes. Stir one quarter of the egg white mixture into the flour mixture to loosen it. Use a rubber spatula to gently fold the remaining egg whites into the batter.
- 5. Pour the batter into the prepared pan and scatter the halved blackberries on top. Bake until golden brown and a toothpick inserted into the cake comes out clean, 35 to 40 minutes. Let cool on a rack for 5 minutes.
- Meanwhile in a medium bowl, combine the remaining 3/4 cup [180 ml] whole milk, the condensed milk, the evaporated milk, the heavy cream, and the vanilla extract. Cut around the edges of the cakes. With a toothpick, poke holes all over the cake and let it soak in. Then pour another 1 cup over the cake. Cover and chill the cake for at least 4 hours or up to overnight.
- Serve slices of the cake with the remaining milk mixture and remaining blackberries. Store leftovers, well-wrapped, in the refrigerator for up to 2 days.