Preheat your oven to 350°F. In a large bowl, beat the softened butter, brown sugar, and granulated sugar until the mixture is light and fluffy. Add the eggs and vanilla extract; mix until well combined.

In a separate bowl, combine the flour, baking soda, baking powder, and salt. Gradually add the dry ingredients to the wet mixture until just mixed; be careful not to overmix.

Gently fold in the chopped Butterfinger pieces until they are evenly distributed throughout the dough.

Using a heaping teaspoon, drop balls of dough onto a baking sheet lined with parchment paper, spacing them at least 2 inches apart. Bake for 12 to 15 minutes, or until the edges are set and lightly browned.

Allow the cookies to cool on the sheet for 5 minutes before transferring them to a wire rack to cool completely.