Preheat the oven to 350℉. Spray a 9x13-inch cake pan with cooking spray.
In a large bowl using an electric mixer, or use a stand mixer with the paddle attachment, combine the dry cake mix, eggs, water, and melted butter. Beat on medium-high speed for 2 minutes, or until the batter lightens in color and is thoroughly combined.
1 box (13.25 oz) chocolate cake mix, 3 large eggs, 1 cup water, 1/2 cup (1 stick) salted butter
Pour the chocolate cake batter into the prepared pan.
Bake for 35-38 minutes, or until a toothpick inserted into the center of the cake comes out clean.
Remove the cake from the oven and allow it cool to room temperature, about 30 minutes, before proceeding.
Use a fork to poke holes all over the chocolate cake.
In a medium bowl, whisk together the sweetened condensed milk, evaporated milk, and chocolate milk. Pour the milk mixture slowly over the cake, allowing it to be absorbed into the small holes as you pour it.
1 can (14 oz) sweetened condensed milk, 1 can (12 oz) evaporated milk, 1 cup chocolate milk
Cover the cake with a lid, plastic wrap, or foil and refrigerate for at least 8 hours or up to overnight.
Prepare the chocolate whipped cream by beating the heavy cream, powdered sugar, cocoa powder, and vanilla extract in a bowl until stiff peaks form. Start at low speed and increase the speed as needed. Evenly spread the chocolate whipped cream over top of the cake.
1½ cup heavy whipping cream, 1/4 cup powdered sugar, 2 tablespoons cocoa powder, 1 teaspoon vanilla extract
Top the whipped cream with milk chocolate shavings/curls. Slice and serve the cake chilled!
chocolate curls/shavings