These s’mores whoopie pies are a fun twist on the campfire classic! Soft graham cookie cakes are filled with a rich layer of chocolate ganache and fluffy marshmallow buttercream. Perfect for parties, gifting, or whenever you're craving something nostalgic and indulgent.
Preheat oven to 350°F (175°C). Line baking sheets with parchment paper.
In a medium bowl, whisk together the flour, graham cracker crumbs, baking soda, baking powder, salt, and cinnamon.
In a large bowl, beat the butter and brown sugar until light and fluffy, about 2–3 minutes. Beat in the egg and vanilla until well combined.
Add the dry ingredients in three portions, alternating with the buttermilk, beginning and ending with the dry. Mix just until combined. (Chill 10-15 minutes if your kitchen is warm so they won’t spread too much.)
Use a cookie scoop (#40, about 1 1/2 tablespoons) to drop mounds of batter onto the prepared pans, spacing them about 2 inches apart. Slightly smooth the tops with damp fingers or the back of a spoon if needed.
Bake one pan at a time for 9–11 minutes, or until the tops are set and spring back lightly when touched. Let cool on the pan for 5 minutes, then transfer to a wire rack to cool completely.
To make the chocolate ganache:
In a small saucepan or microwave-safe bowl, heat the cream until steaming but not boiling.
Pour the hot cream over the chopped chocolate. Let sit for 2–3 minutes, then stir until smooth and glossy. Add a pinch of salt, if using.
Let the ganache cool at room temperature (or briefly in the fridge) until it thickens to a spreadable consistency like soft frosting.
To make the marshmallow buttercream:
In a large bowl, beat the butter until smooth and creamy.
Gradually mix in the confectioners’ sugar until light and fluffy.
Beat in the marshmallow creme, vanilla, and salt until fully combined. The frosting should be fluffy but pipeable. If it’s too soft, chill it briefly.
To assemble:
Pipe or spread ganache on the flat side of half the cooled cakes (about 1–1 1/2 teaspoons per cookie). If necessary, chill for about 5 minutes before adding frosting.
Pipe or dollop buttercream on top of the ganache.
Top with remaining cakes and gently press to sandwich. Garnish as desired.
Chill briefly if needed to firm everything up before serving.
Notes
Graham crumbs: Be sure to use finely ground graham cracker crumbs for the best texture. You can crush them yourself in a food processor or use store-bought crumbs.
Chocolate: Semisweet or bittersweet chocolate works well for the ganache. If you prefer a sweeter filling, use milk chocolate instead.
Marshmallow creme: Brands like Jet-Puffed or Marshmallow Fluff both work. Just make sure you're using the spreadable kind, not actual marshmallows.
Time tip: Plan for about 1 hour of additional time for cooling, chilling the ganache, and assembling the whoopie pies.
Optional garnish ideas: While these are great as-is, you can dress them up with a light chocolate drizzle (melted chocolate with a very small amount of vegetable oil for shine), a sprinkle of crushed graham crumbs, or even a mini toasted marshmallow on top.
Storage: Store whoopie pies in an airtight container at room temperature for up to 2 days, or refrigerate for longer storage. They also freeze well.