Whoopie Pies

🥘 Ingredients

Chocolate Whoopie Pie Cakes

• All-Purpose Flour - Use a spoon to scoop and level your flour for an accurate measurement.
• Unsweetened Cocoa Powder - I prefer Dutch-processed cocoa powder for an extra rich chocolatey flavor, and dark cocoa powder is the second best option. 
• Baking Soda - Baking soda is the leavening agent that gives the cakes their fluffy texture.
• Salt - A little salt helps to balance the sweetness in the cakes.
• Espresso Powder (optional) - A small amount of espresso powder makes chocolate baked goods taste even chocolatier. It's optional, but I recommend giving it a try. I keep a jar of espresso powder handy at all times, just for baking chocolate treats.
• Butter - Let your butter soften at room temperature, do not melt it. Melted butter will make your cakes more dense. The ideal temperature for mixing the butter is 68-70°F (20-21°C).
• Light Brown Sugar - Dark brown sugar has more of a molasses flavor, so I prefer light brown in this recipe. However, you can use either in a pinch.
• Egg - Set the egg on the counter 30 minutes before you start the baking process to let it come to room temperature.
• Vanilla Extract - I always recommend pure vanilla extract for the best flavor.
• Buttermilk - As with all the other cold ingredients for this recipe, let your buttermilk come to room temperature first. I don't recommend using any substitutions here (*see note).

Marshmallow Buttercream Filling

• Marshmallow Fluff - You could make marshmallow fluff from scratch, but the store-bought jars are convenient, inexpensive, and just as tasty.
• Room Temperature - Again, you want the butter to be softened at room temperature, not melted.
• Confectioner's Sugar - Confectioner's sugar, or powdered sugar as many know it, is more fine than granular sugar so it blends into the buttercream seamlessly.
• Vanilla Extract - Vanilla extract for flavor, use pure vanilla for the best results.
• Salt - Another pinch of salt to cut the sweetness.

🔪 How To Make Whoopie Pies

Once you've baked your whoopie pies, the marshmallow buttercream frosting is a breeze then you simply sandwich them together. You'll need a baking sheet, a mixing bowl or two, a hand or stand mixer, and your measuring utensils.

This recipe makes 20 whoopie pies, so there's plenty for potlucks, cookie trays, or sharing just because it's a whoopie pie kind of day.

Make The Whoopie Pie Cakes

Preheat. Preheat your oven to 375°F (190°C/Gas Mark 5) and line a couple of baking sheets with parchment paper.

Sift. Into a large bowl, sift together your 1⅔ cups (208.33 grams) of all-purpose flour, ⅔ cup (57.33 grams) of unsweetened cocoa powder, 1½ teaspoons of baking soda, ¼ teaspoon of salt, and the optional 1½ teaspoons of espresso powder.

Cream butter and sugar. Using a stand mixer or hand mixer, cream together ½ cup (113.5 grams) of butter and 1 cup (220 grams) of light brown sugar until light and fluffy, scraping down the sides and bottom of the bowl as needed.

Beat. Add 1 large egg and 1½-2 teaspoons of vanilla extract and continue to beat until thoroughly combined (about 3 minutes on medium-high speed).

Add half the flour and buttermilk. Stop mixing and add half of your flour mixture as well as half of your 1¼ cup (295.74 grams) of buttermilk.

Mix. Mix on low speed, stopping occasionally to scrape the bowl, until well combined.

Add remaining flour and buttermilk. Add the remaining flour mixture and buttermilk and mix again on low speed until thoroughly combined. It should resemble a very thick cake batter.

Scoop and drop. Use a standard-sized cookie scoop (about 1 - 1½ tablespoons) to scoop the batter and drop it onto your prepared baking sheet, leaving about 2 inches of space in between each one.

Bake. Bake in the oven at 375°F (190°C/Gas Mark 5) for 9-11 minutes, or until the top is no longer shiny and the cake slightly springs back when touched gently.

Cool. Remove the cakes from the oven and let them cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.

Make the Marshmallow Filling

Beat marshmallow fluff and butter. Using a stand mixer or hand mixer, beat together 2 cups of marshmallow creme fluff and 1 cup (227 grams) of butter until light and fluffy.

Mix in sugar, vanilla, and salt. Add 1¼ cups (224 grams) of confectioners sugar, 1½-2 tablespoons of vanilla extract, and ¼ teaspoon of salt and continue to mix until well combined.

Beat until fluffy. Turn the mixer to medium-high and beat for a minute longer. Do not over-mix the frosting, as this can result in a runny filling.

Assemble the Whoopie Pies

Frost. Spread, spoon, or pipe the marshmallow frosting onto the flat side of the cooled cakes.

Assemble and serve. Gently press another cake on top and serve immediately or store them for later.

💭 Angela's Pro Tips & Notes

• Chill before transport. If you are planning on transporting your whoopie pies, I recommend chilling them in the fridge first. This makes them sturdier (and gives them a fudgier texture). 
• Espresso powder makes them extra chocolatey. Adding espresso powder will deepen the chocolate flavor. 
• Buttermilk works best. For this recipe, I recommend using actual buttermilk rather than substituting it for something else. It is the key to activating the baking soda and creating tender cakes. Combining buttermilk from dry powder will still yield great whoopie pies. 😋
• Dutch cocoa has the best flavor. Use Dutch-processed cocoa powder for the best texture and flavor. 
• Shape the dough. If you drop your batter onto your baking sheet in uneven shapes, they will bake unevenly. Use a spoon to gently shape them into circles if needed.
• Cooling completely is key. Your filling will melt and be runny if the whoopie pie cookies are still warm. Allow enough time for cooling to prevent any issues with this.
• Marshmallow creme conversions. The standard 7-ounce size jar of marshmallow creme is only equivalent to 1½ cups. You'll need the 13-ounce jar (approximately 3 cups) to have enough marshmallow creme.

🥡 Storing

Store your whoopie pies in an airtight container at room temperature for up to 4 days. Refrigerate the whoopie pies to keep them stored for up to a week.

Freezing

Whoopie pies can be frozen for up to 2-3 months. Use a sheet of parchment paper between layers if stacking.

Let them thaw overnight in the fridge before serving or bringing them to room temperature.

📖 Recipe Card