Preheat oven to 350°F and prepare two baking sheets with parchment paper, set aside
In a bowl whisk together flour, salt, baking soda and oats and set aside.
With stand mixer and paddle attachment on med-high speed cream together butter and both sugars for about 5 mins. until light and fluffy.
Scrape down bowl, add peanut butter and mix for another min. Then add eggs and vanilla and mix again.
Add flour and oats mixture and mix on low until just combined.
Add mini chocolate chips and M&M's and mix for another 10 seconds making sure not to over mix.
With a large cookie scoop scoop out dough onto prepared cookie sheets and top with extra M&M's and semi-sweet chocolate (optional).
Bake for 10-12 mins. making sure not to over bake as they continue to bake while cooling.
Let them set for 3 mins. before transferring to cooling rack.