01 -
Preheat your oven to 350°F (175°C) and line a 12-cup muffin tin with cupcake liners.
02 -
In a medium bowl, whisk together the graham cracker crumbs, flour, baking powder, and salt. In a large bowl, beat the butter and sugar together until light and fluffy. Add the eggs one at a time, beating well after each addition, then mix in the vanilla extract. Gradually add the dry ingredients to the wet ingredients, alternating with the milk, beginning and ending with the dry ingredients. Mix until just combined. Divide the batter evenly among the cupcake liners, filling each about 2/3 full. Bake for 18-20 minutes, or until a toothpick inserted into the center comes out clean. Allow the cupcakes to cool completely on a wire rack.
03 -
Place the chopped chocolate in a heatproof bowl. In a small saucepan, heat the heavy cream over medium heat until it just begins to simmer. Pour the hot cream over the chopped chocolate and let it sit for 2-3 minutes, then stir until smooth and glossy. Let the chocolate filling cool slightly, then transfer it to a piping bag fitted with a small round tip or a zip-top bag with a corner snipped off. Once the cupcakes are cool, insert the tip into the center of each cupcake and fill with the chocolate mixture.
04 -
In a heatproof bowl or the bowl of a stand mixer, combine the egg whites, sugar, and cream of tartar. Set the bowl over a saucepan of simmering water and whisk constantly until the sugar is dissolved and the mixture reaches 160°F (70°C) on a candy thermometer. Transfer the bowl to the stand mixer fitted with the whisk attachment. Beat on high speed until stiff peaks form and the frosting is glossy, about 5-7 minutes. Mix in the vanilla extract.
05 -
Transfer the marshmallow frosting to a piping bag fitted with a large star tip. Pipe swirls of frosting onto each cupcake. To achieve the classic s’mores look, use a kitchen torch to lightly toast the frosting until golden brown. If you don’t have a kitchen torch, place the cupcakes under the broiler for a few seconds while watching closely to avoid burning.
06 -
Garnish each cupcake with a small piece of graham cracker or a square of chocolate.