Preheat the Oven:
Preheat your oven to 350°F (175°C). Line two baking sheets with parchment paper or silicone baking mats.
Cream the Butter and Sugars:
In a large mixing bowl, use an electric mixer to cream together the softened butter, granulated sugar, and light brown sugar until light and fluffy.
Add Eggs and Vanilla:
Beat in the eggs one at a time, followed by the vanilla extract, until well combined.
Combine Dry Ingredients:
In a separate bowl, whisk together the flour, baking soda, baking powder, and salt. Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Fold in Chocolate Chips and Butterfinger Pieces:
Gently fold in the chocolate chips and crushed Butterfinger candy pieces until evenly distributed throughout the dough.
Scoop the Dough:
Use a cookie scoop or tablespoon to drop rounded balls of dough onto the prepared baking sheets, spacing them about 2 inches apart.
Bake the Cookies:
Bake in the preheated oven for 10-12 minutes, or until the edges are lightly golden and the centers are set but still soft.
Cool the Cookies:
Allow the cookies to cool on the baking sheets for 5 minutes before transferring them to a cooling rack to cool completely.