• Preheat your oven to 375°F. Prepare two 8-inch or 9-inch round cake pans by greasing them thoroughly. For easier cake removal, consider lining the bottom of each pan with a round piece of wax or parchment paper.

For the Cake:

• In a large mixing bowl, whisk together the flour, cocoa, sugar, baking powder, baking soda, and salt. In a separate bowl, beat together the eggs, buttermilk, oil, and vanilla extract. Gradually add the wet ingredients into the dry mixture, stirring until combined. Carefully pour in the boiling water and stir—the batter will become quite thin. Divide the batter evenly between the prepared cake pans.
• Bake for 25 to 35 minutes, adjusting the time according to your pan size. A 9-inch pan may take slightly less time. Test the cakes by inserting a toothpick into the center; if it comes out clean or with only a few moist crumbs, the cakes are done. Let them cool in the pans for about 5 minutes before transferring them onto wire racks to cool completely.

For the Coconut Frosting:

• In a medium saucepan, combine the butter, brown sugar, granulated sugar, egg yolks, and evaporated milk. Stir continuously over medium heat until the mixture begins to bubble and thicken—this should take a few minutes. Remove the saucepan from the heat and stir in the vanilla, pecans, and shredded coconut. Allow the frosting to cool to room temperature before using.
• For the Chocolate Buttercream Frosting:
• Melt the butter in a medium bowl. Gradually mix in the cocoa powder. Add the powdered sugar and evaporated milk in alternating portions, beating the mixture until it reaches a smooth, spreadable consistency. If the frosting is too thick, add a little extra milk; if it’s too thin, mix in more powdered sugar. Finally, stir in the vanilla extract.

Cake Assembly:

• Place one cooled cake layer on your serving plate. Spread a thin layer of chocolate frosting over the top of the cake. Spoon half of the cooled coconut frosting over this, spreading it evenly but leaving a small border around the edge. Place the second cake layer on top. Cover the entire cake with the chocolate frosting, smoothing it over the sides and top. Finish by spooning the remaining coconut frosting over the top of the cake, allowing some of the topping to cascade slightly down the sides for a rustic finish.