Preheat the oven to 375°F. Line baking sheets with parchment paper.
In a large bowl, combine the cookie mixes and oats. Set aside.
In a second large bowl, using a hand mixer, cream the butter. Add the eggs one at a time, and beat until smooth.
Using a wooden spoon, stir in the dry ingredients. Add the M&M candies and festive sprinkles, stirring until a soft dough is formed.
Using a small cookie scoop or a tablespoon, spoon approximately 1 tablespoon of dough onto a parchment-lined cookie sheet, about 2 inches apart. Optionally, slightly flatten each cookie with fingertips or the bottom of a glass.
Bake for 10 minutes, or until the tops of the cookies are beginning to brown. Gently remove cookies to a cooling rack, until cooled. Store in an airtight container.