Preheat the oven to 350 degrees, and prepare cookie sheets by lining them with parchment paper or aluminum foil and spraying with cooking spray.
Combine the peanut butter, butter, brown sugar, and sugar in a large mixing bowl, and stir until smooth. Add the eggs and vanilla and mix until combined well. Stir in the oats and baking soda, making sure to mix really well. Mix in the chocolate chips and M&M's!
Use a measuring cup to scoop out 1/2 c. dough, then roll it into a ball and place on the prepared cookie sheet. I only put three on a cookie sheet, so they would all have room to get big.
Bake for 8-9 minutes, then press them down a little bit with a fork, and bake for another 2-3 minutes, or until golden brown. Let cool for at least 5 minutes, then transfer to a wire cooling rack. Makes 12 cookies.