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

In a large mixing bowl, combine the all-purpose flour, granulated sugar, cocoa powder, baking soda, baking powder, and salt. Mix well to ensure everything is evenly incorporated.

In another bowl, whisk together the eggs, whole milk, vegetable oil, and vanilla extract until smooth and well blended.

Gradually add the wet mixture to the dry ingredients, mixing until fully combined. Be sure to scrape the sides of the bowl to incorporate all ingredients.

Carefully stir in the boiling water, mixing until the batter is smooth. This step will result in a thinner batter, which is normal.

Divide the batter evenly between the prepared pans. Bake in the preheated oven for 30-35 minutes or until a toothpick inserted in the center comes out clean.

In a medium saucepan, combine the evaporated milk, butter, brown sugar, shredded coconut, and chopped pecans. Cook over medium heat, stirring continuously until the mixture thickens.

Once the cakes are cool, layer them with frosting in between each cake layer and spread additional frosting on top and around the sides.