Mocha Tres Leches Cake

Ingredients

For 15 servings

• •1 /2 cup (120 ml) vegetable oil, plus more for greasing
• •10 1/4 ounces all-purpose flour (290 g; 2 1/4 cups)
• •1 c. à soupe baking powder (1/2 ounce; 15 g)
• •1 1/2 ounces Dutch-process cocoa powder (40 g; 1/2 cup)
• •1 /2 cup (120 ml) whole milk
• •2 c. à soupe (10 g) instant espresso powder
• •6 large eggs, separated (350 g)
• •1 c. à café Diamond Crystal kosher salt; for table salt, use half as much by volume
• •10 1/2 ounces granulated sugar (300 g; 1 1/2 cups)
• •1 tasse (240 ml) heavy cream
• •One 12-ounce can evaporated milk
• •One 14-ounce can sweetened condensed milk
• •2 c. à café instant espresso powder
• •1 /8 teaspoon Diamond Crystal kosher salt; for table salt, use half as much by volume
• •1 1/2 cups (355 ml) heavy cream
• •2 1/2 tablespoons confectioners’ sugar (1 1/4 ounces; 35 g)
• •4 1/2 teaspoons Dutch-process cocoa powder, divided
• •1 /8 teaspoon Diamond Crystal kosher salt; for table salt, use half as much by volume
• •1 c. à café ground cinnamon

Method

1. 1.For the Cake: Adjust oven rack to middle position and preheat to 325°F (160°C). Lightly grease a 9- by 13-inch baking pan with vegetable oil.
2. 2.Using a fine-mesh sieve, sift flour, baking powder, and cocoa powder into a medium bowl; set aside. In a small bowl, combine milk and instant espresso powder. Whisk until espresso powder is dissolved, then stir in vegetable oil. Set aside.
3. 3.In the bowl of a stand mixer fitted with the whisk attachment, combine egg whites and salt. Whip on medium speed until egg whites begin to froth, about 1 minute. Then, with mixer continuing to run at medium speed, slowly and steadily pour in sugar. Continue to whisk until meringue is glossy and reaches stiff peaks, about 8 minutes. Add yolks and beat until just combined
4. 4.With the stand mixer running on low, sprinkle in about 1/3 of the flour mixture, then drizzle in 1/3 of the milk and coffee mixture. Repeat with remaining flour and milk, and mix, using a flexible spatula to scrape the bowl and beaters as needed, until batter is well combined, 3 to 5 minutes. Using a flexible spatula, scrape the batter into the prepared pan and bake until a toothpick or cake tester inserted comes out clean and cake springs back when gently touched, 30 to 35 minutes. Set the pan on a wire rack and cool completely, about 1 hour. (Clean mixer bowl and set aside.)
5. 5.For the Soaking Liquid : In a medium bowl, combine heavy cream, evaporated milk, sweetened condensed milk, instant espresso powder, and salt, and whisk until espresso powder has dissolved, about 1 minute.
6. 6.Run an offset spatula or butter knife around edges of cake to loosen. Invert cake onto a cutting board. Using a serrated knife, carefully remove top of cake to level it; set scraps aside for snacking or another use. Return the cake to the pan and, using a skewer or fork, poke holes across surface of cake. Pour half of the soaking liquid all over the cake. Let liquid fully absorb, about 5 minutes, then pour remaining liquid over cake. Loosely cover baking pan with plastic wrap and refrigerate until fully chilled, at least 2 hours and up to 24 hours.
7. 7.To Assemble: In the now-clean bowl of a stand mixer fitted with the whisk attachment, combine heavy cream, confectioners’ sugar, 1 1/2 teaspoons cocoa powder, and salt. Beat on medium-high speed until medium-stiff peaks form, 2 to 4 minutes. Using a flexible or offset spatula, spread whipped cream over cake to cover.
8. 8.Using a fine-mesh sieve, sift remaining 3 tablespoons cocoa powder and cinnamon mixture over whipped cream. Slice and serve.