1. Preheat the oven:

• Preheat your oven to 350°F (175°C) and line baking sheets with parchment paper or silicone mats.

2. Prepare the dough:

• In a medium bowl, whisk together the flour, baking soda, and salt. Set aside.
• In a large bowl, cream the butter, granulated sugar, and brown sugar together until light and fluffy, about 2–3 minutes.
• Beat in the eggs, one at a time, then mix in the vanilla extract.

3. Add the mix-ins:

• Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
• Fold in the M&Ms, chocolate chips, crushed pretzels, and any additional mix-ins like nuts or coconut.

4. Shape the cookies:

• Scoop tablespoon-sized portions of dough and roll them into balls. Place them on the prepared baking sheets, spacing them about 2 inches apart.

5. Bake the cookies:

• Bake in the preheated oven for 10–12 minutes, or until the edges are golden brown and the centers are set.
• Let the cookies cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.

6. Serve and enjoy:

• Store cookies in an airtight container at room temperature for up to 5 days or freeze for up to 3 months.