Preheat the oven to 350°F. You will need 3 cake pans, each 8 inches in diameter. Cut out 3 parchment paper circles that will fit inside the cake pans. Spray the bottom of the cake pans with cooking spray, this is so the parchment paper sticks to the pans. Place the parchment papers inside and spray more cooking spray over the parchment paper.
In a large bowl, whisk together the 2 cups flour, 1½ cups sugar, ¾ cup cocoa powder, 2 teaspoons baking soda, 1 teaspoon baking powder and 1 teaspoon salt.
In a separate bowl, whisk the 1 cup buttermilk, ½ cup vegetable oil, 2 eggs and 1 teaspoon vanilla.
Add the wet ingredients to the dry and mix until just combined. Slowly pour in the 1 cup hot coffee while mixing. The batter will be very thin.
Divide evenly between the 3 pans and bake 35 to 40 minutes, until a toothpick comes out clean. Cool in the pans 10 minutes, then turn out onto a rack and cool completely.
In a saucepan over medium heat, combine the ¾ cup butter, 12 ounces evaporated milk, 1½ cups sugar, 4 beaten egg yolks and 1½ teaspoons vanilla. Cook, stirring constantly, 10 to 12 minutes, until thickened and golden.
Remove from the heat and stir in the 2⅔ cups coconut and 2 cups chopped pecans. Cool to room temperature.
Layer the cakes with frosting between each layer and the rest on top. Refrigerate 1 hour before serving.