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An oatmeal cream pie is the ultimate sandwich cookie treat. Taking inspiration from the classic Little Debbie's Oatmeal Creme Pie, these are a homemade version, combining soft oatmeal cookies with a marshmallowy buttercream filling.
What is an Oatmeal Cream Pie
An oatmeal cream pie (or creme pie, depending on who you're talking to) is a classic American lunchbox treat. They are cookie sandwiches, characterised two soft and chewy molasses oatmeal cookies with a marshmallow-like vanilla buttercream filling. The most famous version is the Little Debbie's brand, which began selling the oatmeal creme pies in the 1930s.
Super Soft Oatmeal Cookies
In order to make these cookies, you'll first need super soft oatmeal cookies!
Ingredients for the Oatmeal Sandwich Cookies:
- Sugar - both light brown muscovado and standard caster (or granulated) sugar.
- Baking Soda and Salt
- Spices - I use a mix of cinnamon and mixed spice.
- And, of course, oats!
Tip for Making Soft Oatmeal Sandwich Cookie
So, one of the trademark elements of the classic Little Debbie's Oatmeal Creme Pie is the super soft thin oatmeal cookie. This can be difficult to recreate at home, especially when most cookie recipes encourage you to aim for a thicker biscuit.
There are a few key tricks to making these soft thin cookies:
- Use melted butter, not just softened.
- Whisk the sugars, molasses and butter together until fully incorporated. The butter will initially try to separate from the sugars, but with a bit of whisking this will all come together as the sugars begin to dissolve into the butter.
- Avoid over-baking and take these out as soon as they start to golden at the edges.
- Let the cookies cool for five to ten minutes on the baking tray before removing to a wire rack.
Why Melted Butter Matters
The consistency of butter matters in baking.
In most cases, you want room temperature ingredients (including butter) so that these mix well together and bake evenly. For cookies, for example, room temperature butter helps keep cookies from spreading too much. In fact, many recipes will suggest chilling the scooped dough before baking, to reduce the spread even further and produce nice thick and chewy finished products. This is the same logic for pastry crusts.
The style of a knock off Little Debbie's Creme Pie demands something a bit different. The goal here is actually a thin cookie, with a bit of a soft bendy finish. This means melting the butter is key.
Melting the butter before using it produces a wetter dough and encourages more spread when baking. The result is a softer thinner final biscuit.
Size of the Oatmeal Cookies for the Oatmeal Cream Pie
You can make either seven giant oatmeal cream pies with this recipe, or about fourteen normal size.
For the giant oatmeal cream pie, I used an OXO #40 Good Grips dough scoop. This dollops out about 1.5 tablespoons of batter, which spread to large cookies.
If you want to make smaller cookies, you can either use a smaller scoop or a kitchen spoon to portion these. As the dough is very wet, they will spoon out and spread easily.
The filling for an oatmeal cream pie is a bit of a contentious question. Many recipes will simply call for a well whipped vanilla buttercream. But, for me the Little Debbie's original has a marshmallowy quality, that demands a bit of marshmallow in the filling.
Ingredients for Vanilla Marshmallow Buttercream
My marshmallow buttercream is quick and easy to whip up with the following:
- Butter - it is important that this is unsalted and at room temperature.
- Powdered icing sugar - if yours is particularly lumpy, it is best to sift this for a smooth finish.
- Marshmallow fluff
- Vanilla extract
Marshmallow Buttercream Process
Making this marshmallow buttercream is very similar to my standard American buttercream recipe, with one big exception:
- Whip or whisk the ingredients - don't worry about adding air. In traditional buttercream, you aren't looking to whip the ingredients into something fluffy as this can cause air bubbles in decorating. For this cream pie filling, you do want a light and fluffy finish.
I used a handheld electric beater to whisk together the butter, marshmallow fluff and powdered sugar. Be careful as the thickness of the fluff might initially make beating difficult, but once this is incorporated it will begin to be smooth.
Add the vanilla and the milk last to form a light and smooth frosting. You can add extra milk if you feel your frosting is too thick or more powdered sugar if you feel it is over runny.
Tips for Filling an Oatmeal Cream Pie
Once you have your cookies and cream, you need to assemble the oatmeal cream pie. This is best done with a piping bag.
- Fill your bag with the frosting.
- Cut off the tip so that you have a 2cm opening.
- Pipe onto the flat base of one of your oatmeal cookies.
- Sandwich this with the base of another cookie.
- Repeat this process until you have paired all of your cookies into sandwiches.
Alternatively, you can make your own DIY piping bag with any square or rectangular plastic bag. Simply fill this with your frosting and cut off a corner as you would cut the tip of the piping bag.
One top tip I have for sandwiching any cookie, is to pre-pair your cookies before beginning to pipe filling.
I'm not great with precision in my cookie sizes, so some are usually on the smaller side and some a bit larger. When you are sandwiching cookies, you want two similar sized biscuits to be paired. Otherwise, you they'll look a bit odd and your filling might overflow the smaller cookie.
By pairing up your cookies before you actually begin to sandwich them with filling, you can ensure that you've matched up similar sizes. These will sandwich nicely, you'll avoid mess and the actual filling process will go more quickly.
FAQs for Oatmeal Cream Pie
Mixed spice is a British blend of warm spices, like cinnamon, nutmeg and allspice. If you don't have access to mixed spice, you can use your own blend of nutmeg and allspice to accompany the cinnamon in this recipe, or replace with pumpkin pie spice, which is a similar blend.
These cookie sandwiches last comfortably for a few days at room temperature in an airtight container. If you have slightly overbaked your cookies, they can in fact improve with a day or two as the cream filling will help to soften the cookies a bit.
Yes, you can freeze these sandwich cookies in a freezer proof container. I would recommend flash freezing them, spread out on a lined tray and then wrapping them individually in cling film before stacking for a more freezer friendly storage.
If you like this recipe, check out some other cookies:
Oatmeal Cream Pies
Soft Oatmeal Cookies
- ¾ cup unsalted butter
- 1 tablespoon molasses or dark treacle
- ⅓ cup light brown muscovado sugar
- ¼ cup sugar
- 1 egg
- ½ teaspoon vanilla extract
- ¾ cup plain or all-purpose flour
- ¼ teaspoon baking soda
- ¼ teaspoon salt
- ½ teaspoon ground cinnamon
- ½ teaspoon mixed spice
- 1½ cups oats
Marshmallow Buttercream Filling
- ½ cup marshmallow fluff about ⅓ of a jar
- ½ cup unsalted butter, softened
- 2 cups powdered icing sugar
- 1½ teaspoon vanilla extract
- 1 tablespoon milk
Instructions for Oatmeal Cookies
- Preheat an oven to 375°F (190C/170C Fan) and line baking sheets with parchment paper or silicone baking mats.
- Place the butter and molasses in a small saucepan and cook over a medium heat until the butter has melted.
- Place the sugars in a large bowl and add the melted butter mixture, whisking together until well combined.
- Add the egg and vanilla to the bowl, whisking to incorporate.
- Next, add the flour, baking soda, salt and spices. Whisk together until just combined.
- Add the oats and mix with a spatula. The dough will look quite wet, but this is to be expected.
- Spoon the cookie dough onto prepared baking sheets, either using a spoon or a cookie scoop. These will spread, so separate them well.
- Bake in the pre-heated oven for about 8 minutes, until the edges begin to turn golden. Watch carefully to avoid overbaking. Remove from the oven and allow to cool for about 5 minutes on the tray before transferring to a wire rack to cool completely.
Instructions for Marshmallow Fluff Buttercream and Assembly
- In a large bowl using an electric hand mixer, beat together the softened butter, powdered sugar and marshmallow fluff until a thick cream. Add the vanilla and milk, beating to combine.
- Pair up your cookies, so that you have matching pairs of two similar sized cookies. Add the marshmallow buttercream to a piping bag and pipe this onto the base of one of the paired cookies, sandwiching together with the other. Repeat until finished sandwiching all pairs.