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, brown sugar, and granulated sugar until light and creamy.

3. Add the eggs and vanilla extract, then mix until smooth.

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

5. Gradually add the dry ingredients to the wet mixture and stir just until combined.

6. Fold in 1 1/4 cups of the Christmas M&M candies, saving the rest for the tops.

7. Scoop the dough into evenly sized balls and place them on the prepared baking sheets, leaving space between each one.

8. Press a few of the remaining M&Ms onto the tops of the dough balls.

9. Bake for 9 to 11 minutes, until the edges are set and the centers still look slightly soft.

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