S'mores Cupcakes

Directions

1. Preheat your oven to the temperature specified on the cake mix box. Line a standard 12-cup muffin tin with paper liners.
2. In a medium bowl, prepare the cake batter following the box directions. Divide the batter evenly among the prepared muffin cups. Bake according to the box instructions, or until a toothpick inserted in the center comes out clean. Allow the cupcakes to cool completely.
3. In a small saucepan over medium heat, bring 1/2 cup of water to a simmer. In a medium heatproof bowl, combine the egg whites and granulated sugar. Place the bowl over the saucepan to create a double boiler. Cook, stirring constantly, until the sugar dissolves and the mixture feels warm to the touch, about 5 minutes.
4. Using oven mitts or a dry towel, carefully remove the bowl from the saucepan. Set the saucepan with water aside for later. Using a handheld mixer on high speed (or a stand mixer with the whisk attachment), beat the egg white mixture until it resembles Marshmallow Fluff and forms soft peaks, about 8 minutes. Stir in the vanilla extract and kosher salt. Transfer the frosting to a piping bag fitted with a large star tip.
5. In a clean medium heatproof bowl, place the semisweet chocolate chips. Carefully set the bowl over the reserved saucepan of simmering water. Cook, stirring, until the chocolate is melted, about 4 minutes. Using oven mitts or a towel, remove the bowl from the heat and keep the chocolate warm until ready to use.
6. Carefully break 2 graham crackers into 12 (1-inch) squares and set aside. Place the remaining 3 graham crackers in a resealable plastic bag and crush them with a wooden spoon or heavy pot to create fine crumbs. Transfer the crumbs to a shallow bowl or plate.
7. Position an oven rack closest to the heating element and turn on the broiler. Dip the edges of each cupcake into the melted chocolate, rotating to coat the rim. Then dip the chocolate-coated edge into the graham cracker crumbs, turning to coat evenly.
8. Pipe the marshmallow frosting onto each cupcake. Arrange the cupcakes on a baking sheet and broil, watching closely, until the frosting is golden brown, about 30 seconds. Garnish each cupcake with a reserved graham cracker square.