*1 cup light brown sugar, packed
*3/4 cup creamy peanut butter (homemade won't work here)
*1/2 cup unsalted butter, softened
*1 tablespoon vanilla extract
*1 3/4 cups all-purpose flour
*3/4 teaspoon baking soda
*pinch of salt
*1 cup Reese's Pieces
*1 cup semi-sweet chocolate chips
1. In a large mixing bowl, cream together the egg, brown sugar, peanut butter, butter, and vanilla extract until light and fluffy, about 5 minutes.
2. Stir in the flour, baking soda, salt, and until just incorporated. (Be sure to scrape down the sides of the bowl) This should only take about 1 minute. Gently stir in the Reese's Pieces and chocolate chips.
3. Use a cookie dough scoop to form mounds of about 2 tablespoons. Place prepared dough mounds on a large plate and flatten slightly with your palm. Cover with plastic wrap and refrigerate for at least 2 hours (up to 5 days) before baking. Chilling the dough will keep it from flattening and spreading in the oven.
4. Preheat oven to 350F and remove dough from the fridge. Line a baking sheet with a silicone baking mat or coat with cooking spray. Place mounds on baking sheet about 2 inches apart. Bake for 8 to 9 minutes, rotating half way through baking. You want the cookies pale and glossy in the center with set edges. Cool on the baking sheet for 5 minutes before removing and transferring to a rack.
5. Keep cooled cookies in an airtight container for up to 1 week or in the freezer for up to 4 months.