Iced Oatmeal Cookie Bars (Little Debbie Copycat!) — The flavor of the classic cookies turned into fast, easy, chewy bars and the frosting is beyond amazing! They’re even better than original Oatmeal Creme Pies!!
Little Debbie Oatmeal Creme Pies were some of my favorite cookies growing up and I could eat a box in a day.
But these iced oatmeal bars are even better.
In doing research for this recipe, I bought a box of Oatmeal Creme Pies. It had been nearly 20 years since I last tried them and unfortunately what I bit into didn’t match my beloved memories. I made it my mission to create a new oatmeal creme cookie recipe that’s worth biting into and I think is better than the original.
I have so many oatmeal cookie recipes because when oatmeal cookies are done right — and by that I mean soft, chewy, and not over-baked — they’re some of my favorites. The chewiness, the perfectly hearty texture, and the nuttiness of the oats speak to me.
Rather than go to the fussiness of making sandwich cookies to recreate the classic Little Debbie cookies, I made bars. Bars are so much faster and easier than cookies since there’s no dough to chill and nothing individual to roll.
The bars are soft, very chewy from the oats, not at all cakey, and perfectly dense. It’s one-bowl, no-mixer batter and you’ll have it from the bowl and into the oven in less than five minutes with only one bowl to wash. Love that.
The icing is buttercream frosting spiked with a jar of marshmallow creme and makes the bars taste truly authentic. It’s sweet, decadent, soft, fluffy, sticky, rich, and you’ll want to eat it by the spoonful.
Ingredients for Iced Oatmeal Cookie Bars
To make this easy recipe for oatmeal bar cookies, you’ll need:
- Butter
- Egg
- Brown sugar
- Molasses
- Vanilla extract
- Salt
- Cinnamon
- Instant oats
- All-purpose flour
- Confectioners’ sugar
- Marshmallow Creme
How to Make Iced Oatmeal Cookie Bars
Making oatmeal bar cookies is even easier than making regular cookies because there’s no dough to chill or roll into balls. Win!
Here’s an overview of how the cookie bars are made:
- Make the bars: Whisk together the melted butter, egg, brown sugar, molasses, cinnamon, salt, and vanilla.
- Add the oats and flour. Stir only until combined.
- Turn the dough into a foil-lined 8×8-inch baking dish.
- Bake the bars until a toothpick inserted in the center comes out clean.
- Make the icing: In a separate bowl, beat the butter and confectioners’ sugar until light and fluffy.
- Add the marshmallow creme and salt and beat until combined.
- Once the cookie bars have cooled completely, top with icing.
Can This Recipe Be Doubled?
Yes! Double the ingredients and bake the oatmeal cookie bars in a 9×13-inch pan.
Can This Recipe Be Made in Advance?
Yes! You can prepare the entire recipe as written a day before serving, or you can store the bars on your counter and pop the icing in the fridge until you’re ready to ice and serve.
Tips for Making Iced Oatmeal Bars
- Use quick-cook oats rather than old-fashioned for the perfect amount of chewiness.
- You’re welcome to add more cinnamon to the bars if you’d like a more pronounced cinnamon flavor.
- You can halve the frosting portion if you’re not a huge frosting person, but I am. The more, the merrier!
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Iced Oatmeal Cookie Bars (Little Debbie Copycat!)
Ingredients
Bars
- ½ cup unsalted butter, melted
- 1 large egg
- 1 cup light brown sugar, packed
- 2 tablespoons medium, dark, or full-bodied molasses
- 1 tablespoon vanilla extract
- ½ teaspoon salt
- ¼ teaspoon cinnamon
- 1 cup instant oats, not old-fashioned or whole-rolled
- ¾ cup all-purpose flour
Frosting
- ½ cup unsalted butter, softened
- 1 ½ cups confectioners’ sugar
- one 7-ounce jar marshmallow creme
- ¼ to ½ teaspoon salt, cuts some of the sweetness
Instructions
Bars
- Preheat oven to 350F. Line an 8-by-8-inch baking pan with aluminum foil, spray with cooking spray; set aside.
- In a large, microwave-safe bowl melt the butter, about 1 minute on high power.
- Wait momentarily before adding the egg so you don’t scramble it. Add the egg, brown sugar, molasses, vanilla, salt, cinnamon, and whisk until smooth.
- Add the oats and stir to combine.
- Add the flour and stir until just combined, don’t overmix.
- Turn batter out into prepared pan, smoothing the top lightly with a spatula. Bake for about 24 to 25 minutes, or until done. A toothpick inserted in the center should come out clean, or with a few moist crumbs, but no batter.
- Place pan on top of a wire rack to cool completely before frosting. Don’t frost warm bars or the frosting will melt.
Frosting
- To the bowl of a stand mixer fitted with the paddle attachment (or large bowl and electric hand mixer), add the butter, confectioners’ sugar, and beat on medium-high speed (start on low so you don’t spray sugar everywhere) until light and fluffy, about 3 minutes.
- Stop, scrape down the sides of the bowl, and add the marshmallow creme, salt, and beat on medium-high speed until well combined, about 1 minute.
- Turn frosting out over bars and lightly smooth it with a spatula or offset knife.
Notes
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
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More Oatmeal Cookie Recipes:
Iced Pumpkin Oatmeal Cookies — Soft and pillowy pumpkin cookies that are chock full of pumpkin spice and everything nice! The icing takes these cookies over the top.
The Best Oatmeal Chocolate Chip Cookies – Soft, chewy, loaded with chocolate, and they turn out perfectly every time! Totally irresistible!
Loaded Oatmeal Chocolate Chip Cookies — Soft, chewy, and loaded with chocolate! Sinking your teeth into a thick, hearty cookie is the best!! So good!
Soft and Chewy Oatmeal Coconut Chocolate Chip Cookies – No butter and no mixer used in these easy cookies dripping with chocolate!
Soft and Chewy Oatmeal Scotchies Cookies – My favorite classic oatmeal cookie base loaded with sweet butterscotch chips! A classic cookie that you’ve just got to try!
These look amazing! My husband would absolutely love these!
Paige
https://thehappyflammily.com
I know you just posted these yesterday, but as soon as I read your post, I knew I had to have them. So I went out to the store today to buy some instant oats, molasses, and marshmallow cream. And here I am eating some amaaazing warm oatmeal bars (no icing yet because I couldn’t wait)! Thanks for the great recipe!
Thanks for trying the recipe and I’m glad it came out great for you even without the icing (which is the BEST PART…haha!) Hope you got to add that and thanks for trying the recipe the day I made it!
These look devine! I think the bars actually look better :)
Little Debbies were my childhood! I loved oatmeal cream pies, and you’re right, they don’t taste the same. I’m totally making this for the kids though, they’d love them!
My husband loves Oatmeal Cream Pies, but I never “let” him get them from the store. Preservatives and all that. This dessert looks like a fantastic alternative, and I love that you made them easier to prepare by going with a bar. Thanks for the recipe, Averie!
Averie I have never eaten oatmeal creme pie before!! I know I am missing out on such a dreamy treat! Thanks to your recipe I will be trying it out soon!
I don’t think I’ve ever had a Little Debbie cream pie (!!!!) but I know I could eat ALL of these bars straight from the pan with a fork!
See that pic with the fork mark, that wasn’t ‘staged’. I had to donate these, promptly :)
Wow, these look so good!
These look so good!
I love all your amazing copycat recipes! I feel so much better about food when I know exactly what goes into it!
I ca totally see how you can eat a box of those a day, your homemade version looks so much better now I can eat a pan of these a day, easilyyyyyy!
I never tried Little Debbies, but these look good. We had a similar disappointing experience with store bought iced circus animal cookies recently! I don’t know if they tasted that bad when we were kids and we didn’t notice or if they’ve lost quality over the years. It’s good to know how to bake!
That’s so funny about the circus animal cookies b/c I loved those things as a kid too! And once when my daughter was a toddler I bought her some of those and had one…blech! Not the same at all as my glowing memories of them :) Same as your experience!
I was such a lover of those oatmeal creme pies too! Such a treat to get one in my lunchbox at school. Loving how these aren’t fussy and easy to make in a bar form. Delicious :)
Oatmeal creme pies and nutty bars were my favorites in high school and I’m sorry to hear the creme pies aren’t the same these days. I remember the marshmallowy middle and something different about the flavor of the cookie ( but never thought about what it might be). Now I realize it had to be the molasses. It looks like you have nailed this one! Homemade always seems to taste better anyway.☺
The molasses is huge in these…and most storebought things are skimpy on it, I’ve determined! And the disappointment that I had after buying a box of OCP’s recently and trying them, not the same at all as what I remember! I loved Nutty Bars too and was recently tempted to buy a box of those but after my last OCP attempt, I thought better of it :)
Isn’t it funny how the food we LOVED as kids is never the same when we try it as adults? The real thing just can’t compete with those happy memories.
I have a lot of nostalgia with these, too. I ate one every day in high school instead of lunch. Not healthy, but so much fun!
Your version looks much better, though. I’m into all that frosting! And it’s not made with hydrogenated anything.
The real thing just can’t compete with those happy memories. <---- Isn't that the truth!! I should have just let those happy memories live in peace and never taken another bite as an adult :)
looks devine!!!! yumm
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