1. Preheat oven to 350 degrees. Grease a mini muffin tin.
2. Cream butter and sugars together until light and fluffy, 3-4 minutes.
3. Add milk, egg and vanilla extract and mix until well combined.
4. Add dry ingredients and mix thoroughly. Dough will be thick.
5. Make balls of about 2 large tsp in size and press into the bottom of each mini muffin cup. Press the center down just a bit to make an indention, where you’ll add the mini snickers later. You want each cup to only be about 3/4 full.
6. Bake for 8-9 minutes.
7. Remove from oven (the centers may look a little undone, but they will cook more as they sit) and press mini snickers into the center of the cookie cups.
8. Allow to cool for 3-4 minutes in the muffin tin. The mini snickers will start to melt.
9. Remove cookies to a cooling rack to finish cooling.
10. To make the frosting, beat the butter and shortening together until smooth.
11. Add the powdered sugar to the butter mixture, one cup at a time, and mix until smooth.
12. Add peanut butter and cocoa and mix until smooth.
13. Add 1-2 tbsp of water until the icing is the right consistency.
14. Top the cookie cups with the icing, then a little bit of caramel sauce.