Preheat oven to 350°F (175°C). Grease and flour three 9-inch round cake pans.

1. In a large bowl, whisk together flour, sugar, cocoa powder, baking soda, baking powder, and salt.
2. Add eggs, buttermilk, oil, and vanilla. Mix until combined, then slowly add boiling water. Batter will be thin.
3. Divide batter evenly into the prepared pans.
4. Bake 30–35 minutes or until a toothpick inserted in the center comes out clean.
5. Cool cakes in pans for 10 minutes, then transfer to wire racks to cool completely.
6. For the frosting: In a saucepan over medium heat, combine evaporated milk, sugar, egg yolks, and butter. Cook, stirring constantly, until thickened (about 10–12 minutes).
7. Remove from heat and stir in vanilla, shredded coconut, and toasted pecans. Let cool to room temperature.
8. Spread frosting between layers and over the top of the cake. Frost sides if desired, though traditionally they are left bare.