1. Preheat the oven to 350°F and line two baking sheets with parchment paper.

2. In a large bowl, beat the softened butter, peanut butter, granulated sugar, and brown sugar until smooth and fluffy.

3. Mix in the egg and vanilla extract until fully combined.

4. In a separate bowl, whisk together the flour, baking soda, baking powder, and salt.

5. Add the dry ingredients to the wet mixture and stir until a soft dough forms.

6. Fold in the Christmas M&M candies and chocolate chips, if using.

7. Scoop the dough into 1 1/2 tablespoon portions and place them on the prepared baking sheets.

8. Press a few extra M&Ms on top of each dough ball for a festive look.

9. Bake for 9 to 11 minutes, until the edges are lightly golden and the centers are just set.

10. Let the cookies cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.