Preheat the oven to 350 degrees.
Line 2-3 baking sheets with parchment and then set aside.
In a large mixing bowl, combine the butter, and peanut butter - beat until smooth.
Add the granulated sugar, brown sugar, eggs and vanilla - beat until blended.
Next add the oats, flour, baking powder, baking soda and salt. Stir until just blended.
Fold in both types of M&M's and the chocolate chips.
Scoop out the dough and roll between your hands to form into balls - about the size of a golf ball.
Place on the prepared baking sheets about 2" apart.
Bake for 12-13 minutes or until golden brown.
Remove from the oven and immediately add additional M&M"s and chocolate chips as desired.
Transfer to a wire rack to cool completely before storing in an airtight container.