Preheat oven to 350 F and line baking sheet with parchment paper. Set aside
In a large bowl, beat butter, white sugar, and brown sugar until light and fluffy. An electric mixer works best for this.
1/2 cup butter, 1/3 cup brown sugar, 1/4 cup white sugar
Use a spatula to fold in the peanut butter. Add in egg and vanilla and continue mixing.
1 egg, 1 tbsp vanilla
Toss in flour, baking soda, and salt. Fold gently until no dry streaks appear. Do not over-mix.
1 1/4 cups all-purpose flour, 1 tsp baking soda, 1/2 tsp salt
Mix in mini Reese's Pieces and white chocolate chips.
Bake 6 cookies at a time for 10-12 minutes or until the edges look a slight golden brown.
Leave the cookies on the baking tray to set. They'll continue to bake as they cool. Now would be the time to add extra add-ins on top if desired. Enjoy!