I remembered that on a recent episode of "The Pioneer Woman," she made some yummy-looking (and theme-appropriate) "monster" cookies that also looked very quick and easy. The recipe calls for everything but the kitchen sink, but it's also very adaptable, so you can use whatever goodies you have on hand or prefer.
PW's Monster Cookies
(Source: adapted from The Pioneer Woman)
1 cup brown sugar, packed
2 whole large eggs
2 teaspoons vanilla extract
1 1/2 cups all-purpose flour
1/2 teaspoon baking soda
1 teaspoon baking powder
1 1/2 teaspoons kosher salt
1 1/2 cups old-fashioned oats
1/2 cup M-n-M's (I swapped out macadamia pieces)
1/2 cup pecans, chopped
3/4 cup chocolate chips (I used bittersweet chunks)
1/2 cups peanut butter chips (I swapped out toffee bits)
2 1/4 cups Rice Krispies
Preheat oven to 375 degrees. Cream butter with sugars until fluffy. Add eggs one at a time, beating well after each addition. Add vanilla and beat.
Combine flour, baking soda, baking powder, and kosher salt. Add to mixing bowl and mix till combined. After that, add in remaining ingredients in whatever quantity you prefer. Add more nuts if you’d like, or more M & M’s, more peanut butter chips or chocolate chips. Add Rice Crispies at the very end, mixing until just combined. Do not overmix!
Use a cookie scoop to scoop balls of dough onto a cookie sheet. (I used a half-sheet pan line with a Silpat, and used a muffin scoop to make six monster-sized cookies per pan.) Bake until golden brown, then allow to cool on a rack. (The large cookies took about 15 minutes to bake, and I got 20 cookies out of one batch of dough.)