Preheat oven to 350°F and line a baking sheet with parchment paper; set aside.
In a large mixing bowl, mix together cookie dough, M&M’s, peanuts, and raisins with a rubber spatula.
Using a medium cookie scoop or large spoon, portion out cookie dough and place on the prepared baking pan, leaving 2 inches between cookies.
Bake for 10 to 12 minutes until the edges begin to turn a golden brown.
Let the cookies cool on the baking sheet for 2-3 minutes, then transfer to a wire cooling rack.
Video
Notes
Substitute different mix-ins, pretty much whatever you like! Just keep the add-ins to no more than 2 cups. More than that will be difficult to incorporate into the dough.
Try a different variety of cookie dough. Peanut butter cookie dough, sugar cookie dough, oatmeal raisin cookie dough -- there's lots of choices!
Make your own cookie dough, if you prefer. Try this recipe for chewy chocolate chip cookies. Omit the chocolate chips and add trail mix ingredients instead.