Step 1: Prepare the cake batter

• Preheat your oven to 350°F (175°C). Grease and flour three 9-inch round cake pans or line them with parchment paper.
• In a large mixing bowl, whisk together the flour, sugar, cocoa powder, baking powder, baking soda, and salt.
• Add the eggs, milk, oil, and vanilla extract to the dry ingredients and beat until smooth. Slowly add the boiling water and mix until the batter is well combined. It will be thin.

Step 2: Bake the cakes

• Divide the batter evenly between the prepared pans. Bake for 30–35 minutes, or until a toothpick inserted in the center comes out clean.
• Let the cakes cool in the pans for 10 minutes, then transfer them to a wire rack to cool completely.

Step 3: Make the coconut-pecan filling

• In a saucepan over medium heat, combine the sweetened condensed milk, butter, and egg yolks. Cook, stirring constantly, until the mixture thickens, about 8–10 minutes.
• Remove from heat and stir in the vanilla extract, shredded coconut, and chopped pecans. Let the filling cool to room temperature.

Step 4: Prepare the chocolate ganache

• In a heatproof bowl, combine the chocolate chips and heavy cream. Microwave in 30-second intervals, stirring between each, until smooth. Stir in the butter until glossy. Let it cool slightly to thicken.

Step 5: Assemble the cake

• Place one cake layer on a serving plate. Spread a generous amount of the coconut-pecan filling on top. Repeat with the second layer.
• Add the third layer and pour the chocolate ganache over the top, letting it drip down the sides. Smooth with a spatula if needed.

Step 6: Garnish and serve

• Garnish with additional coconut and pecans if desired. Let the cake set for 15–20 minutes before slicing.