Preheat oven according to instructions on cookie dough package or the recipe you are using.
Roll chocolate chip cookie dough into 1 inch balls (approximately 1.5 ounces each)
Using a mini muffin tin place one ball in each muffin spot.
Using a tart tamper (or another item with similar width) press down on each ball of dough. This will force the dough to rise up around the inside creating a cup shape. If the dough rises above the edge of the muffin tin you can use your finger to lightly pat it back down so it is even with the muffin tin edge.
Bake the cookie cups according to the instructions on the cookie dough package/recipe. The cookie dough will rise and fill in your cups at this stage. That is normal.
Once the cookies are baked remove them from the oven let cool for 5 minutes. Then use the tart tamper again to press each cookie down in the center where it has puffed up. This should form a perfect cup.
Let the cups cool completely.
When the cookie cups are cooled make your chocolate ganache.
Place the peanut butter in a microwave-safe dish and microwave for 15-30 seconds until it is a pourable consistency. Fill each cup with 1 teaspoon of peanut butter.
Add 1 teaspoon of chocolate ganache to each cookie cup.
Place in the refrigerator to let the ganache firm up.