1/2 cup unsalted butter, room temperature1/3 cup granulated sugar
1/2 cup packed brown sugar
1 large egg
1 tsp. pure vanilla extract
1 1/4 cups plus 2 Tbsp all purpose flour
1/2 tsp salt
1/2 tsp baking soda
1 1/2 cups Butterfinger pieces
Preheat the oven to 350 degrees. In a large bowl, beat the butter and sugars until light and fluffy. Add the egg and vanilla and mix until thoroughly incorporated. In another bowl, combine the flour, salt (if using), and baking soda. Add to the butter/egg mixture and mix until just combined. Stir in the Butterfinger pieces. Chill the dough in the refrigerator for at least 30 min.
Line baking sheets with parchment paper and drop rounded tablespoons of dough. Bake cookies for about 12 minutes or until golden brown. Transfer to wire rack to cool.