Name: Oatmeal Cream Pie Bars
Prep time: 10 min
Cook time: 20 min
Total time: 30 min
Yield: 24 Servings
Cuisine: American
Ingredients: 1/2 cup butter, melted; 1/4 cup vegetable oil; 1 cup brown sugar, packed; 2 eggs; 1 tablespoon vanilla extract; 1.5 teaspoons cinnamon; 1 teaspoon salt; 1/2 teaspoon baking soda; 1/4 teaspoon nutmeg; 1/4 teaspoon ginger; 1 cup flour, packed (see notes); 1.75 cups quick-cook oats; 1 7-oz. tub marshmallow creme; 1 cup salted butter, at room temperature; 1 tablespoon milk or cream; 1 teaspoon vanilla extract; 1 1-lb. box powdered sugar

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A soft and chewy oatmeal cookie bar with a generous slathering of marshmallow buttercream frosting that will remind you of the classic Little Debbie sandwich cookies.

Oatmeal Creme Pies are, hands down, my absolute favorite Little Debbie snack! When I first made the Marshmallow Buttercream Frosting I use on the Easy Cookie Sandwiches, I knew I'd have to figure out a copycat recipe for the oatmeal creme pies because the frosting tastes (and feels) JUST like the creamy filling.

I tried and tried to make a cookie as soft, chewy and moist as Little Debbie's but they would never hold their shape. And any adjustments I made changed the chewiness too much (making them too dry to compare to Little Debbie's).

So I decided to make them into cookie bars! This was the perfect solution because the bars are easy to handle and keep their share but still have the chewy, moist texture. I loooooove them!

Oatmeal Cream Pie Bars! A soft and chewy oatmeal cookie bar with a generous slathering of marshmallow buttercream frosting that will remind you of the classic Little Debbie sandwich cookies.

The batter may seem a little odd to you when you first mix it up. Since we're using melted butter and vegetable oil, it may seem more like a cake batter than a cookie batter.

But once it has cooked and set, you'll see it's more like a cookie. You'll pick these up and eat them just like a cookie... or, I should say, just like a Little Debbie!

These keep and travel well. If you're planning on taking them somewhere, leave them in the pan (and skip the parchment paper). They will stay fresher longer if you leave them in the pan as well (less cookie surface area exposed).

KEY INGREDIENTS & WHY WE USE THEM

BUTTER AND OIL - We use butter for the flavor and body (and melting it helps makes the cookie bar chewy). The vegetable oil also makes the cookie bars chewy but its most important function is keeping them moist.

BROWN SUGAR - You can use either light or dark brown sugar but I highly recommend using dark brown sugar because it has more molasses in it which helps with flavor and color.

SPICES - I'm not 100% sure what exact spices are used in the Little Debbie Oatmeal Cream Pies but I think this combo of cinnamon, nutmeg and ginger gets us pretty close! Feel free to experiment. I imagine you could even use some pumpkin pie spice.

QUICK-COOKING OATS - Also called "instant" oats, quick-cooking oats make for a much more tender cookie base. If you need to use traditional old-fashioned rolled oats, pulse in a food processor once or twice to break the larger grains down a bit.

ABOUT THAT MARSHMALLOW BUTTERCREAM FROSTING...

NOT TOO SWEET - You may look at this and think TOOTHACHE but it's not overly sweet.

CREME VS. FLUFF This recipe was created using Marshmallow Creme (not Fluff). Marshmallow Fluff is a little stiffer but I imagine you could still use it if you reduce the sugar. I'd start with 3/4 of a 1-lb bag/box of sugar then add more if needed.

CONSISTENCY - This has a springy consistency that really holds up (which is why it's so great in cookie sandwiches). It also pipes like a dream if you'd like to use it on cakes!

WHOA, THAT'S A LOT - This recipe does make a generous amount of frosting but it can't easily be halved (1 tub of marshmallow creme and 1 pound of powdered sugar). You don't have to use all of it (I do because I LOVE it). You could probably frost two pan of cookie bars with one recipe of frosting if you'd prefer.

IS IT CREAM OR CREME? They are the same and can be used interchangeably. I use Jet-Puffed Marshmallow Creme because it's easy to find. Other brands spell it "cream" but it's all the same (yummy) stuff. Interestingly, Little Debbie spells it this way in their Oatmeal Creme Pies so maybe that's confirmation that the filling is, in fact, made with marshmallow creme like I've always suspected.

A FEW RECIPE NOTES WORTH READING

DO NOT use the "spoon and sweep" method when measuring the flour for this recipe. Use the measuring cup to scoop the flour from your bin to really pack the flour. If you'd prefer to weigh the flour, we want 150 grams.
Don't add the marshmallow creme before the butter or it will stick to the mixing bowl.
Heat the marshmallow creme 15-20 seconds in the microwave and it will be MUCH easier to spoon out of the container and less sticky to work with. Remove lid and seal before heating.
Unfortunately, you will not be able to use the cookie bar recipe to make individual cookies. Individual portions would spread too much.

MORE DESSERT BAR RECIPES TO TRY!

Chocolate Chip Peanut Butter Oatmeal Bars - An easy chocolate chip cookie bar with peanut butter fudge sandwiched between an oatmeal cookie crumble layer.

Sno Ball Brownies - An easy recipe for fudgy brownies, marshmallow buttercream and coconut just like the classic Hostess Sno Ball snack cakes!

Chewy Chocolate Chip Cookie Bars - All the goodness of chocolate chip cookies made easy in one big easy batch of chewy bars.

Man Bars - An easy and unique cookie bar made with graham cracker crumbs, sweetened condensed milk and chocolate chips, cut and rolled in powdered sugar.

Dubai Chocolate Pistachio Cake Squares - A dessert recipe with easy-to-find ingredients for pistachio cake topped with a crispy chocolate pistachio butter layer.

Recipe for Oatmeal Cream Pie Bars