Instructions

Make the cake

• Position a rack in the center of the oven and preheat the oven to 325°F. Spray three 8-inch cake pans with cooking spray. Line the pans with parchment paper and spray the parchment.
• In a large bowl, whisk together the flour, baking powder, and salt. In medium bowl, whisk together the evaporated milk, eggs, water, and vanilla. Set aside. In a stand mixer fitted with the paddle attachment, mix the butter and sugar on medium-low speed until light and fluffy, scraping down the bowl occasionally, 2 to 3 minutes. Alternating, add the dry ingredients and then the wet ingredients to the butter-sugar mixture in 4 stages, starting with the dry ingredients and ending with the wet ingredients.
• Pour 2/3 cup of batter into each cake pan, spreading the batter evenly to the edges of the pan with a small offset spatula or the back of a spoon. Rap the pan on the counter 1 or 2 times to assure it is evenly spread. Bake until the edges begin to turn light golden brown and the center of the cake springs back when lightly touched, 10 to 12 minutes, or until done.
• Remove the pans from the oven and let cool slightly on a rack. Remove the cakes from the pans, carefully peel off the parchment, and place them on a rack until completely cool. Repeat baking the layers, relining the pans with fresh parchment each time until all the batter is used. You should have 8 to 10 layers.

Make the frosting

• In a 12-inch nonstick skillet, combine the evaporated milk and the sugar and cook over medium heat, stirring occasionally with a wooden spoon, until the sugar dissolves (rub some of the mixture between your fingers to feel if the sugar has melted). Add the chocolate and the butter and cook, stirring frequently, until the mixture becomes smooth and glossy, 10 to 12 minutes. Remove from the heat, add the vanilla, and stir until the mixture is well combined. Let the frosting cool, stirring occasionally, until it becomes a spreadable consistency.

Assemble and serve

• Transfer the first layer, top side down, onto a cake stand or plate. Place about 3 Tbs. of frosting in the center of the cake and using an offset spatula, spread in a thin, even layer to the edges of the cake. Place another layer of cake on top of the icing and repeat with the frosting; continue layering until all of the layers are stacked. Frost the sides of the cake with the remaining frosting. If the frosting cools and becomes too thick to spread, return the pan to the stove and rewarm it on low heat while stirring constantly. Alternatively, after the frosting is made you may want to pour it into a microwave-safe measuring cup for use while frosting the cake. If the frosting begins to thicken, you can reheat it gently in the microwave on low in 10-second increments to soften.
• Serve with the pistachio gelato, if using.

Make Ahead Tips

The cake layers can be made up to 1 day in advance. After they are completely cool, wrap each layer in plastic wrap and store in the refrigerator. Cakes will be easier to frost when chilled.