For the crust:
1 1/3 cup graham cracker crumbs
5 tablespoons of sugar
5 tablespoons melted unsalted butter
For the chocolate cupcakes:
1 cup of sugar
3/4 cup plus 2 tablespoons all-purpose flour
6 tablespoons Hershey’s cocoa powder
3/4 teaspoon baking powder
3/4 teaspoon baking soda
1/2 teaspoon salt
1/2 cup milk at room temperature
1/2 cup vegetable oil
1 large egg, lightly beaten
1 teaspoon vanilla
1/2 cup boiling water
For the marshmallow topping:
2 egg whites
1/2 cup of sugar
1/4 teaspoon cream of tar cream
1 teaspoon vanilla
For the milk chocolate ganache:
1 cup heavy whipping cream
10 oz. milk chocolate, finely chopped
1/2 tablespoon vegetable oil
To make the crust:
Place the rack in the centre of the oven and preheat the oven to 325 F, line the cupcake pans with 16 toppings and set aside.
In a small bowl, combine the graham cracker crumbs, sugar and melted butter and mix well with a fork.
Press about 1 1/2 tablespoons of the mixture into the bottom of each cupcake pan and bake for 6 minutes, then let cool.
To make the cupcakes:
In a large bowl, combine cocoa, sugar, flour, baking powder, baking soda and salt.
Add oil, milk, egg and vanilla. Beat for 2 minutes with an electric hand mixer at medium speed, then add boiling water and beat to combine (dough will be fine). Spread the dough evenly over the crust (it should be 3/4 full).
Cook until a toothpick inserted in the centre comes out clean, about 20-25 minutes. Let cool in the pan, then using a sharp knife or cake lifter, hollow out the centre of each cake (cut off the top of each centre and save it for later to put it back in the filling).
To make marshmallow topping:
In a heat-resistant bowl, over a pan of simmering water, whisk together the egg whites, sugar and cream of tartar until the sugar dissolves (be careful not to let the water touch the bottom of the bowl). Continue whisking over simmering water until the egg mixture is warm to the touch, then remove from heat and continue beating with a mixer until peaks still form. At the end, add vanilla and mix well.
Transfer the filling to a round-ended pastry bag or use a plastic bag and cut off the corner to fill the cupcakes. Replace the tops of the cupcake centres.
To make the ganache:
Over low heat, in a small saucepan, melt the chopped milk chocolate with 1/2 tablespoon of vegetable oil, stirring until the mixture is completely smooth. Remove from heat and add cold heavy whipped cream, stirring well until well blended. Using a spoon, spread the ganache on the cupcakes. If the ganache should run, place it briefly in the refrigerator to set before filling the cupcakes.