Combine butter and sugar.
Cream together butter and sugar.
mix in peanut butter.
Mix in the vanilla and eggs.
Mix until its taken on a light, creamy, fluffy texture.
Add in your dry ingredients.
Mix until the dough is formed.
Preheat the oven to 350°F/175°C.
Form the cookie dough into 1" balls and place them into the muffin tray. Bake for 10-12 minutes.
After removing from the oven while still hot, place a mini peanut butter cup into each cookie and allow to cool before removing from pan.
And you're finished.