Preheat oven to 350°F. Butter and flour three 8-inch round baking pans.

In the bowl of your mixer, stir together sugar, flour, cocoa, baking powder, baking soda, and salt. Add eggs, milk, oil, and vanilla; beat on medium speed for 2 minutes. Stir in boiling water. Pour batter into prepared pans.

Bake 20-37 minutes or until wooden pick inserted in center comes out clean. Cool 10 minutes, then remove from pans to wire racks. Cool completely.

In the bowl of your mixer, beat butter, peanut butter, whipping cream, and vanilla on medium-low speed. Add marshmallow cream and beat on medium until smooth. Slowly beat in powdered sugar until just barely mixed. Increase speed to high and beat for one minute, until fluffy.

Place one cake layer on a plate and top with half of the frosting. Top with another cake and repeat, topping with the final cake. Place in the refrigerator while you prepare caramel and chocolate.

In a microwave safe bowl, heat caramel and cream, stopping to stir every 30 seconds until smooth.

Pour over the top center of cake, spreading to the edges and letting it drip down the sides.

Place back in the refrigerator.

Melt butter in a small saucepan over medium heat. Whisk in cocoa powder and milk until mixture thickens and begins to boil.

Remove from heat and whisk in powdered sugar.

Pour over top center of cake, spreading to the edges and letting the excess drip down the sides.

Garnish with chopped candy bars and peanuts.