In a mixing bowl, using an electric hand mixer, beat the butter, cream cheese, and peanut butter until it's thoroughly combined and creamed together well. The mixture should be much lighter in color and look creamy.
4 tablespoons salted butter, 4 oz cream cheese, 1/2 cup creamy peanut butter
Add in the light brown sugar and vanilla extract. Beat until combined.
½ teaspoon vanilla extract, 1 tablespoon brown sugar
Add in the powdered sugar, quick oats, mini chocolate chips, and mini m&m's. Beat on low speed (increase the speed as needed) until combined well.
1¼ cups powdered sugar, 1 cup quick oats, 1/2 cup mini chocolate chips, 1/2 cup mini m&m's Christmas mix
Use a rubber spatula or your clean hands to form the cookie dough into a ball. The dough should not be so sticky that you can't form and handle it into a ball.
Place the cookie dough ball onto a plate. Gently press the mini m&m's into the sides and all over the top of the cookie dough ball until it's completely covered.
additional m&m's for the outside
Cover the cheeseball with plastic wrap and refrigerate for at least 2 hours before serving.*You can serve the cheeseball right away but it will be much softer. It does taste better chilled after the flavors have time to meld together. The dip is firm immediately from the fridge, but as it sits out at room temperature it will soften up making it easy to dip. Serve with your favorite dipping options like graham crackers, pretzels, mini Oreos, mini Chips Ahoy, Nilla Wafers, shortbread cookies, etc.