Preheat oven to 350 degrees F.

Grease and flour 2 (8-inch) round cake pans. Sift together dry ingredients including flour, sugar, baking powder, and salt. Add the shortening, milk, eggs, and vanilla. Beat mixture until smooth then add the peanut butter. In a microwave safe bowl, melt the caramel squares with whipping cream for about 1 minute. Add the caramel mixture to the batter and mix well. Pour the batter evenly into the pans and bake for 25 to 30 minutes or until a toothpick inserted into the center of the cake comes out clean. Cool in the pan for 10 minutes, then turn out onto on a wire rack until completely cool.

Sprinkle chopped peanuts in between the layers and place on a freezer safe plate. Ice cake with caramel icing. Place in the freezer for 30 minutes. Place the cake back onto the wire rack with a cookie sheet underneath to catch the ganache. Pour the ganache over cake the cake, coating completely and allow to dry before placing on a serving plate. Garnish as desired while ganache is still wet.