OOH! Keto whoopie pies. Yes, please! I’ll have two.
These little marshmallow filled cakes are sticky, gooey, and sweet, just like the originals. The filling tastes like marshmallow fluff, without any aftertaste or graininess — the perfect little treat to beat back a sweet craving.
These whoopie pies are:
- Low Carb
- Refined Sugar-Free.
Low Carb Whoopie Pies – Come on, You Know You Want One.
These are one of those sweet treats that feel like you’re cheating.
They clock in less at than four net carbs per serving, and a serving is pretty substantial. I’d be lying if I said I couldn’t finish one. I did, and I thought about a second one. But one is more than adequate as a treat.
They are sticky, just like real marshmallow fluff; as a matter of fact my entire kitchen was sticky after making these, but I am a messy baker.
What are the best sweeteners for these whoopie pies?
The best sweeteners for the cakes
For the whoopie pie cakes, you can use your favorite sweeteners at a 1:1 ratio. Erythritol, xylitol, and monk fruit all work perfectly.
I used So Nourished powdered monk fruit erythritol blend because I like it best in baking recipes. It blends well and has no aftertaste.
The only sweetener I would not recommend is stevia, as I find (this is a personal preference) stevia becomes very bitter when mixed with chocolate.
**And remember if you use Xylitol that it is poisonous to your dogs and cats. **
The best sweeteners For the marshmallow fluff
For the marshmallow fluff, you need to use allulose.
Nothing else will work, trust me, I tried. Allulose hardens when heated, and that’s the property we need for this recipe to work.
I tried blending erythritol and allulose, but it doesn’t work the same way. Allulose gets sticky, and hardens with heat.
Tips to get the cakes perfect
So a few tips to get your cakes to rise correctly.
- Make sure you sift all your dry ingredients. Sifting removes any lumps in the flours and the sweeteners. Sifting also adds a bit of air into the dry ingredients and helps to lighten up the batter.
- Blend the wet ingredients until the mixture is light and fluffy. Add it to the dry ingredients all at once.
- Blend until just mixed. Do not over mix. Over mixing creates a heavy batter and a dense cake. The mixture will be very thick, much thicker than a boxed cake mix. You may feel the mix is wrong, but it bakes up perfectly.
- I used a muffin top pan, but you do not need to. The muffin top pan does help to create perfect rounds, but if you’re not genuinely fussy about perfectness, you can make these on a cookie sheet. An ice cream scoop works perfectly to drop rounds that bake up all the same size.
- Tap down the batter mounds with wet fingers, or the back of a damp spoon. Make sure the tops are smooth.
- The whoopie pies are finished baking when the center springs back, or a toothpick inserted comes out clean. You do not want to over bake them as they will be dry.
Tips to make the (almost) carb-free marshmallow fluff
Working with allulose is a tiny bit different than working with sugar. If you cook allulose too quickly on high, it will brown, and it will be bitter.
- Mix the water and the allulose in a high-walled pan or pot. Stir it gently. If you get any allulose up on the walls of the pan, it will burn and fall back into your mixture. Those little burned bits add bitterness to the final dessert, so try to avoid it if you can.
- Use a wet pastry brush to wipe the allulose off the sides of the pot or pan before heating to prevent burning. DO NOT cook on high; you have to cook this mixture on medium heat until it reaches 260F. It takes about 10 minutes. Slow cooking ensures the allulose does not burn.
- Whip the egg whites in the bowl of a stand mixer while the allulose is cooking on the stove. Turn the mixer to medium speed and gently pour the hot syrup into the egg whites slowly. Wear gloves. This stuff is hot and burns just like hot sugar. Whip for 5 minutes on high, until the mixture is glossy and stiff and holds a peak. Let it cool for a few minutes before adding it to a piping bag.
This marshmallow fluff is made with egg whites and allulose – almost carb-free! The carb count on two heaping tablespoons is negligible.
keto Whoopie pie assembly
These whoopie pies come together quickly. Once the cakes are cold to the touch, you can slice them in half like a hamburger bun. Go gentle; the cakes are tender.
Xanthan gum is required in this recipe to hold everything together. Without gluten, there is nothing to bind the ingredients together, so we need to replace the gluten with something.
I like to use xanthan gum because a tiny little bit makes a huge difference in low-carb and gluten-free baking.
Once you slice the cakes, go ahead and either pipe or spoon in the marshmallow fluff. Since the fluff has barely any carbs, I piled it on.
Sometimes you want something sweet and sticky, and I went overboard with my marshmallow filling. My recommendation is you do the same.
I piped in two layers of fluff, so every single bite came with a squish of sweet vanilla goo.
I stacked mine for photographs, but I don’t recommend stacking them for storage. The fluff will ooze out of the lower whoopie pies. But they hold together just fine without any sticky overflow if they are stored single layer.
Serving and Storage Suggestions
You can store these keto whoopie pies in the fridge, no worry about graininess because the allulose doesn’t grain up in the cold like erythritol or xylitol will.
The filling is delicious out of the fridge; the texture changes a tiny little bit making even more like the original jar of marshmallow fluff.
These are best on the first day. If you fill them all at once, be sure they will be consumed the same day. Or keep the cakes in the fridge separate from the fluff and fill them as you want them.
You can store the unfilled cakes sliced in the freezer also, so you don’t have to make them all up at once. The marshmallow fluff lasts in the fridge for three days.
Chocolate Whoopie Pie Cakes
- 2 eggs
- 1/4 cup unsweetened almond milk
- 1/4 cup melted unsalted butter
- 1 ounce melted unsweetened bakers chocolate
- 2/3 cup powdered erythritol monk fruit blend (or your favorite low carb sweetener)
- 1 cup almond flour
- 1/2 cup coconut flour
- 1 Tbsp cocoa powder
- 1 tsp baking powder
- 1/3 tsp Xanthan gum
- 1 tsp vanilla
- A pinch of salt
Marshmallow Fluff Filling
- 1 1/2 cups allulose
- 2/3 cup water
- 2 large egg whites
- 1 tsp vanilla
- A pinch of salt
Chocolate Whoopie Pie Cakes
- Preheat oven to 350F.
- Prepare a muffin top pan by spraying with a non-stick spray, or grease 10 wells with butter or coconut oil.
- Add eggs to a mixing bowl and mix on high for 2 minutes.
- Melt the butter in the microwave, but do not overheat. We want the butter soft, but not too hot.
- Chop up the bakers chocolate into small pieces and melt in the microwave in 30-second increments until the chocolate is completely melted.
- Add vanilla, almond milk, melted butter, and melted bakers chocolate to egg mixture and blend until well incorporated.
- Sift almond flour, coconut flour, baking powder, xanthan gum, salt, cocoa powder and powdered erythritol in a large bowl.
- Gently add the egg mixture to the dry ingredient mixture. Do not over mix.
- Fill muffin top pan with 1/4 cup of batter in each well. Gently pat down the top to even out the batter. See notes for additional baking pan options.
- Bake in a 350F oven for 10-12 minutes or until a toothpick inserted in the center of a cake comes out clean.
- Remove from oven and cool the whoopie pies in the pan for 20 minutes before removing.
Marshmallow Fluff Filling
- In a medium saucepan, add allulose and water. Stir gently to incorporate. Use a wet pastry brush to wipe down the walls of the pan.
- In the bowl of a stand mixer, whip 2 egg whites with a pinch of salt and whip until soft peaks form. Turn the stand mixer off.
- Over medium heat cook the allulose and water mixture to 260F. Use a candy- or digital-thermometer to measure the temperature. If the allulose starts to brown before it hits 260F, the heat is too high. Do not stir during cooking.
- Turn the stand mixer back on, and slowly pour the allulose syrup into the egg mixture. Use an oven mitt, the syrup is very hot.
- Turn the stand mixer up to high, add the vanilla and blend for 4-6 minutes or until the mixture is glossy and holds a peak.
Whoopie Pie Assembly
- Slice cooled cakes in half.
- Pipe or spoon 1/4 cup of marshmallow fluff into the center of each whoopie pie.
- Add the tops and store covered in a single layer inside the refrigerator.
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Powdered Monk Fruit Sweetener with Erythritol Confectioners (1 lb / 16 oz)
Bob's Red Mill Almond Flour
Anthony's Organic Coconut Flour
Anthony's Xanthan Gum
Hoosier Hill Farm ALLULOSE Low Calorie, Zero Net Carb Keto Sugar, Natural Sugar Alternative, Made in the USA, Granular Powder, 2 lb bag, batch tested gluten free
Nutrition Information:Yield: 10 Serving Size: 1
Amount Per Serving: Calories: 132Total Fat: 8.8gSaturated Fat: 1.7gTrans Fat: 0gUnsaturated Fat: 6.1gCholesterol: 37mgSodium: 33mgCarbohydrates: 8gNet Carbohydrates: 3.4gFiber: 4gSugar: .5gProtein: 6g
Nutritional information for the recipe is provided as a courtesy and is approximate only. We cannot guarantee the accuracy of the nutritional information given for any recipe on this site. Erythritol carbs (and sugar alcohols) are not included in carb counts as it has been shown not to impact blood sugar. Net carbs are the total carbs minus fibre.