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

In a large bowl, whisk together flour, sugar, cocoa powder, baking powder, baking soda, and salt.

Add buttermilk, oil, eggs, and vanilla. Beat until well combined. Gradually add hot coffee; batter will be thin.

Pour batter evenly into prepared pans. Bake for 30-35 minutes, or until a wooden skewer inserted into the center comes out clean.

Let cool in pans for 10 minutes before inverting onto a wire rack to cool completely.

In a medium saucepan, combine evaporated milk, sugar, butter, and egg yolks. Cook over medium heat, stirring constantly, until thickened, about 10-12 minutes.

Remove from heat and stir in vanilla, coconut, and pecans. Let cool slightly before frosting cake.

Place one cake layer on a serving plate. Spread with frosting. Repeat with remaining layers. Frost the top and sides of the cake.

Refrigerate for at least 30 minutes before serving.