In a stand mixer, cream together the butter, peanut butter, brown (or coconut) sugar, and white sugar until smooth.
Add the eggs and vanilla extract, mixing until just combined.
Gradually add the flour, baking soda, and salt, and mix until well incorporated.
Stir in the oats until evenly distributed.
Fold in the mini M&M’s, crushed pretzels, and chocolate chips until they're evenly distributed throughout the dough.
Refrigerate the dough for 30 minutes to prevent spreading during baking.
Preheat your oven to 350°F and line a baking sheet with parchment paper.
Form 14 jumbo cookies, each about the size of a small fist, and place them on the baking sheet.
Bake for 10-12 minutes until the cookies are golden brown on top and slightly soft to the touch.
Remove from the oven and let them cool on the baking sheet for 10 minutes.
Now, it's time to indulge! Enjoy your freshly baked Jumbo Christmas Monster Cookies with a tall glass of milk for the ultimate treat.
Pro tip: These cookies are best enjoyed with a cozy cup of milk!