Instructions:
Preheat oven: Preheat your oven to 400°F (200°C). Grease a sheet pan.
Combine dry ingredients: In a large bowl, whisk together the flour, sugar, and cocoa powder.
Melt wet ingredients: In a small saucepan, combine the water, butter, shortening, and German baking chocolate. Bring to a boil over medium heat. Stir constantly until smooth and combined.
Combine wet and dry: Pour the melted mixture into the dry ingredients and whisk to combine.
Add remaining ingredients: Stir in the buttermilk, baking soda, salt, eggs, and vanilla.
Bake: Pour the batter into the prepared sheet pan and bake for 20-22 minutes, or until a toothpick inserted into the center comes out clean. Let cool completely before frosting.
Make the frosting: In a medium saucepan, combine the evaporated milk, egg yolks, butter, sugar, and brown sugar. Bring to a boil over medium heat. Reduce heat and simmer for 10-12 minutes, stirring frequently, or until thickened.
Add toppings: Remove from heat and stir in the coconut, pecans, and vanilla.
Frost the cake: Let the frosting cool slightly before spreading it over the cooled cake.
Chill: Chill the cake for 1-2 hours before serving.
