In a large bowl combine Butter, Peanut Butter, Eggs, Cake Mix and slowly add milk stirring till completely combined.
Fill lined muffin tin 2/3 full then press a reese cup in the center of the cupcake till it is even with batter. Then take a little drop of batter and spread over reese cup. Bake for 18 mins or till toothpick inserted at a angle comes out clean.
Ganache ~ While cupcakes are baking we are going to mix the Icing.
In a double boiler combine Milk Chocolate, Heavy cream, and Butter. Stir till smooth and creamy. Take off the heat and add vanilla stirring till combine then Set aside.
Once the cupcakes are done let cool in pan for 10 mins before moving to a wire rack. Let icing and cupcakes cool a total of 20mins. When completely cool stirring the icing every few mins. Then dip the tops into the chocolate just above the rim of the cupcake liner. Set on tray and let excess icing drip off. Now Eat and Enjoy!