Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans.
In a large bowl, whisk together the flour, sugar, cocoa powder, baking soda, baking powder, and salt for the cake layers.
Add the eggs, buttermilk, vegetable oil, and vanilla extract to the dry ingredients. Beat with an electric mixer on medium speed for two minutes.
Carefully stir in the hot water or coffee until the batter is smooth. The batter will be thin.
Divide the batter evenly between the prepared cake pans.
Bake for 30 to 35 minutes, or until a wooden pick inserted into the center comes out clean. Let the cakes cool in the pans for 10 minutes before inverting them onto a wire rack to cool completely.
Prepare the Coconut-Pecan Frosting: In a medium saucepan, combine the evaporated milk, 1 cup granulated sugar, and 1/2 cup butter. Cook over medium heat, stirring constantly, until the butter melts and the mixture is smooth.
In a separate bowl, lightly whisk the egg yolks. Slowly temper the yolks by whisking a small amount of the hot milk mixture into the yolks, then pour the yolk mixture back into the saucepan.
Cook over medium-low heat, stirring constantly, until the mixture thickens enough to coat the back of a spoon (do not boil). Remove from heat.
Stir in the toasted pecans, toasted coconut, vanilla extract, and salt. Let the frosting cool completely to room temperature; it will thicken as it cools.
Prepare the Chocolate Glaze: In a small bowl, whisk together the melted butter, cocoa powder, powdered sugar, and milk until smooth.
Assemble the cake: Place one cooled cake layer on a serving plate. Spread about half of the coconut-pecan frosting evenly over the first layer. Top with the second cake layer. Spread the remaining coconut-pecan frosting over the top layer.
Drizzle the chocolate glaze over the top of the cake. Allow the glaze to set slightly before slicing.
Notes
For the moistest cake layers, use hot brewed coffee instead of hot water; the coffee deepens the chocolate flavor without making the cake taste like coffee.
Toasting the coconut and pecans enhances their flavor significantly. Spread them on a baking sheet and bake at 350°F (175°C) for 5-8 minutes, watching closely to prevent burning.
If you are interested in meal planning for desserts, this recipe pairs well with structured approaches like a keto meal plan delivery if you adapt the sugar content.