When I make them, I use extra m&m's to decorate the top. They look pretty that way, and you can do different colors for the holidays too.
Recipe by Sheila at musings of a mommy.blogspot.com
2 sticks of butter
1 lb. brown sugar
2 cups white sugar
2 Tbsp. vanilla
3 cups peanut butter
4 tsp. soda
9 cups quick cooking rolled oats
½ lb. M&M’s
½ lb. chocolate chips
Mix all ingredients. I use a cookie scoop to measure them out on the cookie sheet. Bake at 350 on greased cookie sheets for 10-15 minutes, or until the edge of one cookie starts to brown just a teeny bit. These taste better on the under-done side, as they set up as they cool. Makes 6 dozen.