Whoopie pies are two soft cocoa cookies sandwiched around a fluffy marshmallow filling — somewhere between a cookie and a cake, and better than either on its own. This recipe makes 8 pies in about an hour, and the whole process is straightforward enough to do on a weekday afternoon. The buttermilk batter comes together fast, the filling takes two minutes, and the result is something people genuinely get excited about.
The short version of why this works
Two things matter here. First, alternating the dry ingredients and buttermilk when mixing — starting and ending with the dry — keeps the batter from getting tough or curdled. The buttermilk also reacts with the baking soda to give the cookies their lift and that slightly tender crumb. Second, not overbaking. Pull the cookies when the tops spring back to a light touch, even if they look underdone at the edges. They firm up as they cool, and an extra two minutes in the oven is the difference between a pillowy cookie and a dry one.
Troubleshooting
- Cookies spread too thin and flat: Your butter was probably too warm. Softened means it holds a fingerprint but isn’t greasy. If your kitchen is hot, chill the scooped dough mounds for 15 minutes before baking.
- Filling is too loose to hold its shape: The butter wasn’t soft enough before beating, or the marshmallow creme was cold. Both should be at room temperature. If it’s still runny, add powdered sugar a tablespoon at a time until it holds a peak.
- Cookies are domed and uneven, so the sandwich won’t sit flat: Use a cookie scoop and flatten each mound very slightly with damp fingers before baking. Pair cookies by size when assembling — a slight mismatch in height matters more than a mismatch in width.
- Filling squeezes out the sides when you press the sandwich together: You’re using too much. A heaping tablespoon is the right amount. Pipe or spoon it onto the center of the flat side and leave a small border — it will spread when pressed.
- Cookies stick to the parchment: They need a few minutes to set on the pan before you move them. If one tears, it wasn’t cool enough yet. Wait another two minutes and try again.
Substitutions that actually work
- Buttermilk: If you don’t have it, stir 1½ teaspoons of white vinegar or lemon juice into ½ cup of whole milk and let it sit for five minutes. It works just as well here.
- Dutch-processed cocoa: Natural unsweetened cocoa is fine, but the cookies will be slightly less dark and a touch more bitter. Either works — skip the expensive single-origin stuff for this recipe, it won’t make a noticeable difference once baked.
- Marshmallow creme: Store-brand marshmallow creme behaves the same as Fluff in this filling. Skip making homemade marshmallow creme — not worth the extra dish.
- Unsalted butter: Salted butter works in both the cookies and the filling; just leave out the added salt in the cookie dough.
Storage and make-ahead
Assembled whoopie pies keep well at room temperature in an airtight container for up to 2 days — layer them between sheets of parchment so they don’t stick together. For longer storage, refrigerate for up to 5 days, but let them sit out for 20 minutes before eating so the filling softens back up. You can also bake the cookies up to 2 days ahead and store them unfilled at room temperature, then make the filling and assemble the day you need them. Filled pies freeze well for up to 6 weeks; wrap each one individually in plastic wrap, then place in a zip bag. Thaw at room temperature for about an hour.
Decadent Chocolate Whoopie Pies
Ingredients
For the chocolate cookies:
- 2 cups all-purpose flour Preferably organic.
- ½ cup unsweetened cocoa powder Best quality, such as Dutch-processed.
- 1 teaspoon baking powder Ensure freshness.
- ½ teaspoon baking soda
- ¼ teaspoon salt
- ¾ cup unsalted butter softened to room temperature.
- 1 cup granulated sugar Prefer fine-grain.
- 1 teaspoon vanilla extract
- 1 large egg
- ½ cup buttermilk At room temperature.
For the filling:
- 1 cup marshmallow creme Fluff brand for authenticity.
- ½ cup unsalted butter softened.
- 1 cup powdered sugar Sifted for smooth texture.
- 1 teaspoon vanilla extract
Instructions
- Preheat your oven to 180°C (350°F) and line two baking sheets with parchment paper.
- In a large bowl, whisk together the flour, cocoa powder, baking powder, baking soda, and salt until fully combined.
- In another bowl, using an electric mixer, cream together the softened butter and sugar on medium speed until light and fluffy, about 3 minutes.
- Add the vanilla extract and egg to the creamed mixture, then beat until well incorporated.
- Gradually add the dry ingredients to the wet ingredients, alternating with the buttermilk, beginning and ending with the dry ingredients. Mix just until combined.
- Using a cookie scoop, drop 2-tablespoon-sized mounds of dough onto the prepared baking sheets, leaving ample space for spreading.
- Bake for 8-10 minutes or until the tops spring back when lightly touched. Let cool on the baking sheet for a few minutes before transferring to a wire rack to cool completely.
- To make the filling, beat together the marshmallow creme, softened butter, powdered sugar, and vanilla extract in a medium bowl until smooth and fluffy, about 2 minutes.
- Match cookies of similar size and spread or pipe a heaping tablespoon of filling onto the flat side of one cookie, topping with another cookie to form a sandwich. Repeat with remaining cookies.
Notes
Nutrition
Frequently asked questions
Can I make these without an electric mixer?
Yes, but creaming the butter and sugar by hand takes real effort — plan on 5 to 7 minutes of vigorous stirring with a wooden spoon to get it light enough. The filling is easier to do by hand since marshmallow creme is already soft, though a hand mixer gets it fluffier in less time.
Why do my whoopie pie cookies come out cakey instead of fudgy?
Cakey is actually correct for whoopie pies — that soft, cake-like texture is the whole point. If they feel too dry or crumbly rather than tender, the most likely cause is overbaking or too much flour; spoon the flour into the measuring cup rather than scooping directly from the bag.
Can I double the recipe to make more than 8 pies?
Yes, doubling works without any adjustments to technique or timing. Just bake in batches on two pans and rotate them halfway through if your oven runs hot in the back — the bake time stays the same at 8 to 10 minutes per batch.
What to bake next
- Chocolate Cream Pie
- Maple Cream Sandwich Cookies
- Malted Milk Chocolate Cake
- Gourmet Vanilla Bean Marshmallows