1 1/2 cups creamy or chunky peanut butter
1 cup packed light brown sugar
1 cup granulated white sugar
1/2 cup (1 stick) unsalted butter, softened
3 large eggs
1 tablespoon vanilla extract
4 1/2 cups quick cooking oats
2 teaspoons baking soda
1 cup semi-sweet chocolate chips
1 cup M&M's plain chocolate candies
Preheat oven to 350°F. Spray cookie sheets with nonstick spray. In a large bowl, combine the peanut butter with the sugars and butter. Use an electric mixer to mix until well combined. Mix in the eggs and vanilla. Mix in the oats and baking soda. Then stir in the chips and M&M's.
Drop the cookies by heaping spoonfuls onto the prepared cookie sheets. If you'd like your cookies to look pretty, dot a few extra M&M's and chocolate chips on each mound of dough before baking.
Bake 10 to 12 minutes. Do not overbake. Cool for 5 minutes on cookie sheets until cookies are set. Transfer to wire racks; cool completely before storing in an airtight container.