Step 1

Preheat oven to 400 degrees F and grease a sheet pan.

Step 2

In a large bowl, mix together the flour, sugar, and cocoa powder.

Step 3

In a small saucepan, add the water, butter, shortening, and chocolate. Bring to a boil over medium heat. Once the mixture is smooth and fully combined, add it to the dry ingredients and whisk to combine.

Step 4

Stirring between each addition, first add the buttermilk, baking soda, salt, eggs, and then vanilla.

Step 5

Transfer batter to the prepared sheet pan and bake for 20-22 minutes. Let cool before frosting.

Step 6

Add the milk, egg yolks, butter, and sugars to a medium sized saucepan over medium heat. Bring mixture to a boil and then lower heat to a simmer. Stir frequently and continue cooking for 10-12 minutes or until mixture has thickened. Remove from heat.

Step 7

Stir in coconut, pecan, and vanilla.

Step 8

Let frosting cool slightly and then spread over the cooled cake.

Step 9

Chill for 1-2 hours, then serve.