Preheat your oven to 350°F (175°C) and line two baking sheets with parchment paper.
In a large bowl, cream together the softened butter, brown sugar, and granulated sugar until light and fluffy, about 3-4 minutes.
Beat in the eggs one at a time, then add the vanilla extract and mix until well combined.
In a separate bowl, whisk together the flour, baking soda, and salt.
Gradually add the dry ingredients to the wet ingredients, mixing just until combined.
Stir in all the mix-ins: chocolate chips, white chocolate chips, M&M's, crushed pretzels, nuts, coconut, and toffee bits. The batter will be thick and packed with goodies!
Drop rounded tablespoons of dough onto the prepared baking sheets, spacing them about 2 inches apart.
Bake for 10-12 minutes, or until the edges are lightly golden but the centers still look slightly underdone.
Let the cookies cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely. Store in an airtight container for up to 5 days.