Preheat oven to 350 degrees. Line a baking sheet with parchment paper.
Cream together the butter, peanut butter, and sugars. Beat in the egg until light and fluffy.
In a medium bowl, whisk together the dry ingredients. Add the dry ingredients to the wet and mix until just combined. Stir in the chocolate chips.
Place two tablespoons of cookie dough on the prepared baking sheet and smash down a bit. Place a candy bar in the center. Drop another tablespoon of dough on top of the candy bar and cover the candy bar with the dough. The cookies will spread quite a bit to be around 4 to 5 inches in diameter, so place them far apart on the baking sheet.