Preheat oven to 350 degrees.
Line cookie sheet with a Silpat Baking Pad or parchment paper. Set aside.
Using a Stand Mixer fitted with the Paddle attachment, cream together the Butter and Sugars until light and fluffy (about 2 minutes).
Add the eggs, one at a time, mixing well. Add the vanilla and continue mixing until all is blended, scraping down sides of bowl as needed.
In a separate bowl, combine the Sifted GF Flour, Salt, Baking Powder and Baking Soda.
Note: please be sure to sift the flour since it helps prevent grittiness.
Add the Flour mixture to the Butter mixture. Mix until well-combined.
Next, add the Oats and Chocolate Chips and mix until incorporated. Note: add the chopped nuts now if you're including them.
Lastly, add the M&M Candies and Rice Cereal and mix well using a large, sturdy spoon.
Using a 2 Tbsp cookie scoop, drop dough balls at least 2" apart onto the prepared cookie sheet. I only placed 8 cookie dough balls on each baking sheet.
Bake in preheated oven for 10-14 minutes, rotating pan halfway through. Cookies are done when they turn a light golden brown.
Let cookies cool for a couple of minutes on baking sheet, before transferring to a wire cooling rack.
These cookies store well in an airtight container for 3-5 days, if they last that long! They also ship well...I send these cookies to one of my daughters, who states that they arrive looking like they were just baked :)