Chop the Chewy Granola bars into small pieces and set aside.
Use an electric mixer to beat the butter with the sugar until light and fluffy. Beat in the egg, vanilla and peanut butter.
Whisk together the flour, baking powder and salt in a separate bowl. Mix well and add to the peanut mixture. Beat until incorporated. Fold in the chopped Chewy Granola bars. Refrigerate for 1 hour or until very firm.
Preheat the oven to 350°F and line two large baking sheets with parchment paper. Roll the dough into 1-inch balls and place about 2 inches from each other on the baking sheets. Use a fork to flatten and make crosshatch marks on top. Bake until lightly browned around the edges, 12 to 15 minutes. Cool on wire racks.