Preheat your oven to 375°F (190°C). Line two large baking sheets with parchment paper.

In a large bowl using a stand mixer or a hand mixer, cream together the softened butter, light brown sugar, and granulated sugar on medium-high speed until light and fluffy, about 2-3 minutes.

Beat in the eggs one at a time, mixing well after each addition. Scrape down the sides of the bowl as needed. Stir in the vanilla extract.

In a separate medium bowl, whisk together the all-purpose flour, baking soda, and salt.

With the mixer on low speed, gradually add the dry ingredients to the wet ingredients, mixing until just combined. Do not overmix.

Gently fold in all the mix-ins: semi-sweet chocolate chips, white chocolate chips, crushed potato chips, crushed pretzels, toffee bits, and Christmas M&Ms/sprinkles. The dough will be very chunky.

Drop rounded tablespoons of dough (about 1.5 tablespoons each, or use a medium cookie scoop) onto the prepared baking sheets, spacing them about 2 inches apart.

Bake for 10-12 minutes, or until the edges are golden brown and the centers are set. For a festive touch, you can press a few extra M&Ms or sprinkles onto the tops of the hot cookies right after they come out of the oven.

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