Blend butter, brown sugar, and white sugar in a mixer. Add eggs, vanilla, corn syrup and peanut butter and blend until combined.
Add baking powder, baking soda, oatmeal and flour and mix well until everything is well blended.
Stir in M&Ms and chocolate chips.
Using a cookie scoop (or just a spoon!) scoop dough into balls (about 1″) on a cookie sheet about 2″ apart. Just slightly flatten dough balls.
Bake at 350 degrees for 9-11 minutes until lightly brown. If you make larger cookies, they will need to cook longer (11-14 mins).