Monster Cookies
Delicious, chewy monster cookies, made with chocolate chips, M&Ms, and lots of peanut butter. This recipe has only oats and no flour, which makes them 100% whole grain, and gluten-free if you use gluten-free oats!
Servings: 60
Calories: 142kcal
Equipment
- electric mixer
- medium (#40) cookie scoop
- silicone mats or parchment paper
Ingredients
- 8 tablespoons butter (113 grams; softened)
- 1 ½ cups peanut butter (384 grams)
- 1 ¼ cup brown sugar (250 grams)
- 1 cup granulated sugar (200 grams)
- 1 ½ teaspoon corn syrup (10 grams; optional but recommended)
- 3 eggs (~150 grams)
- 1 ½ teaspoon vanilla extract (7 grams)
- 4 ½ cups rolled oats (360 grams; old-fashioned or quick are both fine)
- 2 teaspoons baking soda
- 1 cup chocolate chips (170 grams/6 ounces)
- 1 cup M&Ms (212 grams/7.5 ounces)
Instructions
- With a stand mixer or hand mixer, combine butter, peanut butter, sugars, and corn syrup. Mix at medium speed for 1-2 minutes, until mixture has lightened in color.
- Scrape the bottom, and then add vanilla and eggs. Mix again on medium speed for about 1 minute, until everything is combined. Scrape the bottom again to look for unmixed bits.
- Add in the oats and the baking soda. (Switch to a rubber spatula if you were using a hand mixer.) Stir on low until everything is mixed in, pausing to scrape the bottom as you go.
- Add the chocolate chips and M&Ms. Stir on low just to combine.
- Using a medium, 1 ½ tablespoon (or #40) cookie scoop, or two spoons, portion dough onto parchment or silicone-lined baking sheets, leaving 2 inches between cookies.
- Bake at 350F for 10-12 minutes. (11 is perfect in my oven, but yours may be different.) The tops will look set and dry, and they will be slightly browned and a little puffy on top, though they will deflate as they cool.
- Cool for 5-10 minutes before removing from the baking sheets.
Freezer Instructions/Make-Ahead
- Scoop the cookie dough onto plates or cookie sheets lined with waxed paper or plastic wrap. Crowd them on as closely as possible, without letting them touch.
- Freeze dough until solid. Remove the balls of cookie dough and store them in a labeled freezer bag.
- To bake, heat your oven to 350F. Place balls of cookie dough 2 inches apart on your parchment-lined sheets. Bake, from frozen, for 12-14 minutes.
Notes
These cookies are gluten-free if you choose certified gluten-free oats. Although oats are naturally gluten-free, they are often processed on the same machinery as flour, leading to cross-contamination.
Use regular grocery store creamy peanut butter. Do not use "natural" peanut butter that has no added oil or sugar, that that you have to stir and store in the fridge; cookies will not turn out right if you do.
Corn syrup is optional, but recommended. Corn syrup helps keep the cookies soft and chewy. The cookies will be delicious without it on day 1, and often still good on day 2. But by day 3, the cookies made without corn syrup will start to seem stale.
Both old-fashioned oats and quick-cooking oats work fine in this recipe. I often have both and use a mix. Do not use instant oats (too mushy) or steel-cut oats (which are too thick to cook fully).
These cookies freeze incredibly well. Bake one or two sheets when you make the dough, and follow the freezer instructions to save the rest of the dough for later.
To make giant cookies, use a ¼ cup to measure dough. Bake for a few extra minutes, until the tops of the cookies look set.
Calorie count calculated in MyNetDiary and is an estimate only.
Recipe revised slightly 8/27/2025.
Nutrition
Calories: 142kcal
