If you love M&M’s, you’re gonna go crazy for these M&M oatmeal cookie bars! Made with oatmeal cookie crust, a thick, delicious fudge center and topped with oatmeal crumble and M&M candies. The ultimate MM cookie bars recipe!
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Are M&M’s your favorite candy? If so, then these MM Oatmeal Cookie Bars are a must make.
Made with a simple oatmeal cookie crust, then filled with a fudgy, chocolate center. Topped with more oatmeal crumble and loads of your favorite M&M chocolate candies.
Perfect for a bake sale, a sweet lunchbox surprise or even a treat to share with friends at work.
What do I need to make M&M cookie bars?
Here’s a quick reference check list of the ingredients you’ll need to make these oatmeal cookie bars:
- Oatmeal – quick or old fashioned rolled oats
- All purpose flour
- Brown sugar
- Baking soda
- Sweetened condensed milk (1, 14 oz. can)
- Semi-sweet chocolate chips
- Plain M&M chocolate candies
For exact ingredient amounts and full recipe instructions, please reference the recipe card at the bottom of this post.
How do I make cookie bars?
Cookie bars are quite simple to make. This recipe includes an oatmeal cookie crust, a chocolate fudge filling, and is topped with more oatmeal crumble and M&M candies.
Here are the simple steps to making these cookie bars:
- Start by making the oatmeal cookie crust. Mix together the oatmeal, flour, brown sugar, soda and salt. Then pour 3/4 cup of melted butter over this mixture, and mix with a fork. It will be crumbly and gravel-like. Reserve 1/4 of this mixture for the topping, and press the remaining 3/4 of the mixture into the bottom of a 9×13″ pan. Set aside.
- Next make the chocolate filling by microwaving the sweetened condensed milk, chocolate chips and butter together. Microwave until all ingredients are melted together and smooth. Pour this mixture over the top of the oatmeal crust.
- Sprinkle the reserved oatmeal crumble over the top of the chocolate layer.
- Lastly, sprinkle the M&M’s over the oatmeal crumble. Bake the bars at 350 for 20 minutes.
How long should cookie bars cool?
Once cookie bars come out of the oven, they will need to cool to room temperature before cutting into squares. A minimum of 1 hour or until they are no longer warm to the touch.
Much like brownies, if you were to cut hot/warm cookie bars, they will tear, be messy and and not be of uniform shape.
How many bars does a 9×13″ pan hold?
A 9×13″ pan will render 15-20 medium-sized cookie bars. Depending on the size of bar you prefer, you can slice rows of 3×5 (three bars on short side, five bars on long side) to render 15 bars. For 20 cookie bars, slice 4×5 (four bars on short side, 5 bars on long side) to render 20 bars.
These mm cookie bars are wonderfully sweet and quite rich, so going smaller may be better.
Not only are these great for a bake sale, they’re fantastic for a classroom treat or a fun after-school snack. I’ve also served these for my girlfriends for a book club night, and they disappear just as fast as the wine.
I’ve also sent these in with my husband for a work pot-luck, and the pan always comes home completely empty.
FAQ’s about making cookie bars:
Yes. Cookie bars will keep, covered, at room temperature for up to 3 days. For best results, store cookie bars in an air-tight container in the refrigerator. Refrigerated they will keep for up to 7 days.
Yes. Once completely cool, MM cookie bars can be frozen. Freeze, wrapped in a freezer bag, or in an airtight freezer container. Frozen, they will keep for up to three months. Before serving, let thaw to room temperature.
Cookie bars are a type of dessert square or bar that is more firm than cake, but softer than a cookie. They have similar ingredients to cookies, however, are baked in one pan and cut into squares, instead of spooned out or rolled into individual cookies.
It depends on the recipe and amount of ingredients used. However, either a 9×13″ pan or a jelly-roll pan is best for making cookie bars. Pans will need to have a minimum of a 1″ edge to contain the baked bars.
Do you love cookie bar recipes? Check out some of our post popular bars and cookies:
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Love M&M treats? Check out some of our other best M&M cookies, bars and treats:
Oatmeal Crust and Topping:
- 1 1/2 c. oatmeal (quick or old fashioned rolled oats)
- 1 1/2 c. all purpose flour
- 1 c. brown sugar
- 1 tsp. baking soda
- 1/2 tsp. salt
- 3/4 c. butter, melted
- 1 c. M&M chocolate candies, plain (reserved for topping)
- 1 (14 oz.) can, sweetened condensed milk
- 1 c. semi-sweet chocolate chips
- 1/3 c. butter
- Preheat oven to 350 degrees. Lightly spray a 9x13" pan with non-stick baking spray. Set aside.
- In a bowl, combine the oatmeal, flour, brown sugar, soda and salt. Mix until combined and the brown sugar has broken apart. Pour the 3/4 c. melted butter into the mixture and mix with a fork until crumbly. Set aside a quarter of this mixture for the topping. Press the remaining oatmeal mixture into the bottom of the prepared pan to form a crust. Set aside.
- In a microwave safe bowl, add the sweetened condensed milk, chocolate chips and 1/3 c. butter. Microwave on high for 1 minute. Stir. Microwave for another 30 seconds and stir until smooth. Chocolate chips should be completely melted. Pour this chocolate mixture over the top of the prepared oatmeal crust.
- Using the reserved oatmeal mixture, sprinkle this over the top of the chocolate. Sprinkle the M&M candies over the top of the oatmeal mixture.
- Bake at 350 degrees for 20 minutes. Once done baking, let the bars cool completely (at least 1 hour) before cutting into squares.
Recipe will make 15 large squares or 20 medium squares.
Store any leftovers at room temperature, covered in an airtight container. At room temperature, will keep for 3 days. Kept refrigerated, the bars will last for up to 7 days.
Bars can be frozen. Store in a freezer bag or airtight, freezer-safe container. Will keep for up to 3 months.
Nutrition Information:Yield: 20 Serving Size: 1 bar
Amount Per Serving: Calories: 269Total Fat: 15gSaturated Fat: 9gTrans Fat: 0gUnsaturated Fat: 5gCholesterol: 29mgSodium: 213mgCarbohydrates: 32gFiber: 1gSugar: 21gProtein: 3g