Easy Texas Turtle Sheet Cake

Ingredients:

2 cups granulated sugar
2 cups self-rising flour
1 cup butter
1 cup strong black coffee
1/3 cup unsweetened cocoa powder
2 eggs
1/2 cup buttermilk
chocolate frosting:
1/4 cup butter
4 tablespoons buttermilk
3 tablespoons unsweetened cocoa
2 1/2 cups powdered sugar
turtle topping:
1/2 cup chopped pecans
1 cup semi-sweet chocolate chips
1 cup caramel sauce, to drizzle