I was planning on shipping some treats in the mail, and since this cookie is fairly sturdy I thought it would travel well and be a nice addition to my package of goodies. I have made these cookies numerous times and they are always a crowd favorite. The M&M's can be mixed right into the batter, but I think it is more visually appealing to set them on top of the cookies before they bake.
Adapted Slightly From The King Arthur Flour Cookie Companion
3 large eggs
1 cup brown sugar
1 cup granulated sugar
1 teaspoon vanilla extract
1 teaspoon corn syrup
2 teaspoons baking soda
1 teaspoon salt
1/2 cup (1 stick) unsalted butter, melted
1 1/2 cups smooth peanut butter
4 1/2 cups rolled oats
1/2 cup all-purpose flour
3/4 cup semi-sweet chocolate chips
3/4 cup butterscotch chips
3/4 cup M&M's (mini or regular size)
1. Preheat oven to 350 degrees F. Line baking sheets with parchment (or lightly grease).
2. In a large mixing bowl, combine the eggs, sugars, vanilla, corn syrup, baking soda, and salt. Stir in the melted butter, then the peanut butter, oats, and flour, mixing until thoroughly combined. Stir in the chips and candy. Let the dough rest for 30 minutes so the oats can absorb some of the butter.
3. Drop by scant 1/4-cupfuls onto the prepared baking sheets. Use your fingers to flatten cookies slightly, then bake for 12 minutes, until cookies are a light golden brown. Cool on wire racks.