Preheat the Oven:
Preheat your oven to 350°F (175°C).
Line baking sheets with parchment paper or silicone baking mats.
Mix the Dough:
In a large mixing bowl, cream together the softened butter and granulated sugar until light and fluffy.
Add the egg and vanilla extract, beating well to combine.
Combine Dry Ingredients:
In a separate bowl, whisk together the flour, baking powder, and salt.
Gradually add the dry ingredients to the butter mixture, mixing until just combined.
Add Pretzels and M&Ms:
Gently fold in the broken pretzel pieces and holiday M&Ms until evenly distributed.
Form the Cookies:
Using a cookie scoop or spoon, form the dough into 1 1/2-inch balls.
Roll each ball in granulated sugar to coat.
Bake the Cookies:
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 are set.
Cool the Cookies:
Allow the cookies to cool on the baking sheets for a few minutes before transferring them to a cooling rack to cool completely.