Prepare the Dough : In a large bowl, cream together the softened butter, dark brown sugar, and granulated sugar until light and fluffy, about 2–3 minutes. Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.

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.

Add the Mix-Ins : Gently fold in the M&M’s, white chocolate chips, crushed pretzels, potato chips, and holiday sprinkles. Be careful not to overmix to avoid crushing the mix-ins too much.

Chill the Dough : Cover the dough with plastic wrap and refrigerate for at least 30 minutes. This step helps the cookies maintain their shape during baking.

Bake the Cookies : Preheat your oven to 350°F (175°C) and line baking sheets with parchment paper. Scoop about 1 ½ tablespoons of dough per cookie and roll into balls. Place the dough balls on the prepared baking sheets, spacing them about 2 inches apart. Bake for 10–12 minutes, or until the edges are lightly golden and the centers look slightly underbaked.

Cool the Cookies : Remove the cookies from the oven and let them cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.

Serve and Enjoy : Serve these cookies fresh or store them in an airtight container at room temperature for up to 5 days.