Preheat your oven to 350°F (175°C) and prepare your baking sheets by lining them with parchment paper or silicone mats.

In a large mixing bowl, beat together the softened unsalted butter, packed light brown sugar, and granulated sugar until light and fluffy, about 2-3 minutes.

Add the large eggs one at a time, followed by the vanilla extract, mixing until everything is well combined.

In a separate bowl, whisk together the all-purpose flour, baking soda, and salt. Gradually add this to the wet mixture, mixing on low until just combined.

Fold in the crushed Butterfinger bars, caramel bits, and chopped peanuts gently with a spatula.

Drop the dough onto prepared baking sheets using a cookie scoop or tablespoon, spacing about 2 inches apart.

Sprinkle a tiny pinch of sea salt flakes on each mound of dough, then bake for 10-12 minutes, until the edges are golden brown.

Allow cookies to cool on the baking sheets for about 5 minutes before transferring to a wire rack.