German Chocolate Cake

For the Chocolate Cake:
2 cups all-purpose flour
1 ¾ cups granulated sugar
¾ cup unsweetened cocoa powder
1 ½ teaspoons baking powder
1 ½ teaspoons baking soda
1 teaspoon salt
2 large eggs
1 cup whole milk
½ cup vegetable oil
2 teaspoons vanilla extract
1 cup boiling water
For the Coconut-Pecan Frosting (Traditional German Chocolate Frosting):
1 cup evaporated milk
1 cup granulated sugar
3 large egg yolks
½ cup unsalted butter
1 teaspoon vanilla extract
1 ½ cups sweetened shredded coconut
1 cup chopped pecans
Optional Chocolate Ganache (for decoration):
1 cup semi-sweet chocolate chips
½ cup heavy cream