made with a chocolate graham cracker cake and marshmallow fluff filling topped with crushed graham crackers. these s'mores whoopie pies are soft, chewy, a little cake-y, with hints of that classic s'mores flavor.
stand mixer with paddle attachment or electric hand mixer with beaters
large baking sheets (2)
medium cookie scoop (about 2 tbsp)
cooling rack (2)
whoopie pie cakes
1 3/4 c (210g)all purpose flour
1/2 c (55g)graham crackers, processed into very small crumbs
1tsp baking powder
1/2tsp baking soda
1/2 c (113g)unsalted butter, room temperature
1 1/4c (250g)light brown sugar
1/2c (43g)dutch process cocoa powder
1tsp espresso powder
1(57g)large egg, room temperature
1(18g)large egg yolk, room temperature
1tsp (5ml)vanilla extract
1c (240ml)whole milk, room temperature
1/2 c (113g)salted butter, room temperaturesub 1:1 with unsalted + 1/4 tsp salt
4 tbsp (57g)unsalted butter, room temperature
1 1/2 - 2 c (188-250)powdered sugar, sifted
10-11oz. marshmallow fluff about 1 1/2 (7 oz.) containers
2tsp (10ml)vanilla extract
3-4 "sheets" of graham crackers for topping, optional
whoopie pie cakes
Using a food processor, process the graham crackers until a flour like consistency (very fine crumbs). Pour into a medium sized mixing bowl. Whisk together the ground graham crackers, flour, baking powder, baking soda and salt. Set aside.
In a stand mixer with paddle attachment, beat the butter on medium speed until smooth and creamy. Scrape the sides and bottom of the bowl. Sift in the cocoa powder and espresso powder. Beat on low until just incorporated. Add the sugar and beat on medium speed until smoothand well combined, about 1-2 minutes. Scrape down the sides and bottom as needed. Add the egg and yolk, beat on medium speed until smooth, about 30 - 60 seconds. Scrape the bottom and sides of the mixing bowl.
By hand or on the lowest setting on the mixer: In this order, add the milk and dry ingredients to the wet : dry, milk, dry, milk, dry. Mix each time until just incorporated. Scrape the bottom and sides of the bowl as needed to ensure everything is mixing well. The batter will look pretty liquidy. Place the batter in the fridge to chill for about 45-60 minutes. The batter is ready when it has the consitency of thick chocolate mousse. It should easily hold its shape when scooped.
30 minutes before you plan to bake the cookies, preheat the oven to 375 F (190 C). Line 2 large baking sheets with parchment paper and set aside.
Using a small (2 tbsp) cookie scoop, drop scoops of cookie batter onto the line baking sheet about 2-3" apart. Place the remaining batter back in the fridge. Bake the first sheet of cakes on the middle rack of a 375F (190 C) oven for 14-15 minutes. The cookies will spread and puff a little in the center. The edges will look set. A finger lightly pressed into the center of a "cookie" will bounce back. If not, bake 1-2 minutes longer until this happens.
Place the baking sheet on a cooling rack to cool for 5 -10 minutes or until lukewarm to the touch. Gently seperate the cookies from the baking sheet using a spatula. Transfer the cookies to a cooling rack to fully cool.
In a stand mixer with paddle attachment, on medium speed, beat the butter, 1 1/2 c powdered sugar and fluff and vanilla together until smooth and well combined. Taste and adjust flavors or textures as needed (eg, more powdered sugar, vanilla or salt). If anything is added, beat the mixture for an additional 60 seconds or until well combined.
The filling is easiest to pipe onto the cookies when chilled in the fridge for 15-20 minutes. If desired, scoop the marshmallow filling into a frosting bag or zip lock bag.
Assembling the whoopie pies
Turn 1/2 of the cooled cakes with the bottom of the cookie facing up. Apply the filling. Top the filling with crushed graham crackers, if desired (I recommend this!). Top each frosted cake with another cake "cookie." Gently press down. Enjoy!
Storing and serving :The cookies are easiest to eat when taken from the fridge or freezer. If not serving right away, place the prepared whoopie pies on a large lined baking sheet or serving platter to chill in the fridge. Whoopie pies should be loosely covered with plastic wrap. Whoopie pies should not be stacked. If stacking is needed, place a piece of parchment or wax paper across the top of the bottom layer of whoopie pies.
To freeze, wrap each whoopie pie individually in wax paper. Place the wrapped whoopie pies in a freezer proof container. To serve, set out at room temperature for 10-15 minutes.