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

In a large mixing bowl, combine flour, sugar, cocoa powder, baking powder, baking soda, and salt. Whisk until well mixed.

Add eggs, milk, vegetable oil, and vanilla extract. Mix on medium speed for about 2 minutes until fully blended.

Mix in the boiling water until combined. Pour equal amounts into the prepared cake pans.

Bake for 30 to 35 minutes or until a toothpick inserted in the center comes out clean. Allow to cool in pans for 10 minutes before transferring to wire racks to cool completely.

In a medium saucepan over medium heat, combine evaporated milk, sugar, butter, and egg yolks. Cook, stirring constantly, until thickens (about 12-15 minutes).

Remove from heat and stir in the vanilla, coconut, and pecans. Allow cooling to room temperature.

Once the cake layers are cool, place one layer on a cake stand or plate.

Spread a generous amount of frosting on top. Add the second layer and frost the top and sides.

Add extra toasted pecans on top if desired and serve.