Fluffy chocolate sponge cake soaked in a chocolate three-milk mixture and topped with chocolate whipped cream, this Chocolate Tres Leches Cake is a creamy and chocolatey treat that's perfect for any occasion.
Preheat the oven to 320℉/160℃. Line the bottom and sides of an 8-inch/20 cm square pan with parchment paper. Set aside.
In a large bowl, add hot milk and instant coffee. Sift in the cocoa powder and whisk until well incorporated. Add egg yolks and vegetable oil. Whisk until combined.
Sift in cake flour and baking powder. Whisk until well incorporated. Set aside.
In a medium bowl, add egg whites and cream of tartar. Beat on low-medium speed with a hand mixer until frothy. Gradually add granulated sugar to the egg white mixture while the mixer is running. Increase the speed to high speed and beat until glossy and stiff peaks form.
Transfer one-third of the egg white mixture to the egg yolk mixture. Fold with a spatula until well combined. Add the remaining egg white mixture in 2 additions, gently folding it into the egg yolk mixture each time. Don't overmix.
Transfer the batter to the prepared pan. Spread evenly with a spatula. Run a skewer through the batter to remove the air bubbles. Tap the pan a few times on the counter.
Bake for 35 minutes or until a toothpick inserted in the center comes out clean. Remove the cake from the pan and cool completely on a cooling rack.
Chocolate Milk Bath
In a medium bowl, add hot milk and sift in cocoa powder. Mix until well incorporated. Add evaporated milk and condensed milk. Mix until combined.
Invert the cake over parchment paper (the paper should be bigger than the cake for easy lifting). Peel the parchment paper on top.
Lift the parchment paper on the bottom to transfer the cake back into an 8-inch/20 cm square pan. The cake should shrink during cooling, so it should fit the pan. If not, you can transfer the cake into a slightly bigger pan.
With a fork, poke lots of holes into the cake. Pour the chocolate milk bath over the top.
Cover with cling wrap and refrigerate for at least 1 hour to allow the cake to soak up the milk.
Chocolate Whipped Cream
In a medium bowl, add heavy whipping cream. Sift in confectioners' sugar and cocoa powder. Beat on high speed until stiff.
Transfer the cake onto a cutting board. Spread chocolate whipped cream on top evenly.
Trim the edges with a knife. Cut the cake into 9 slices. Wipe the knife clean after each slice for clean cuts.