- Heat oven to 350°F.
- In large bowl using hand mixer cream peanut butter, butter and brown sugar until light and fluffy. Add egg and vanilla extract until combined.
- In small bowl, combine flour, peanuts, baking soda and salt. Gradually add flour mixture to peanut butter mixture and mix just until flour is incorporated.
- In small bowl, combine sugar and cinnamon.
- Scoop heaping tablespoon cookie dough and flatten. Top with truffle and wrap dough to completely seal.
- Roll in cinnamon-sugar mixture and place on parchment paper-lined baking sheet.
Bake 10 minutes or until edges are set. Let stand 5 minutes before transferring to wire rack to cool.