Prepare an 8-inch round cake pan: Butter, line the bottom with a round of parchment, butter again, and flour. Place a rack in the center of the oven, then heat the oven to 350°F.

Using a whisk, hand mixer, or stand mixer fitted with the whisk attachment, beat the egg whites until frothy. While still beating, slowly stream in ¼ cup of sugar until the whites become stiff and glossy.

In a large bowl, whisk the graham cracker crumbs, flour, the remaining ¼ cup of sugar, baking powder, and salt. Add the yolks, milk, oil, and vanilla. Using a whisk, hand mixer, or a stand mixer fitted with the paddle attachment, mix for 1 to 2 minutes until the batter has lightened in color.

Using a spoon or flexible spatula, fold the egg whites into the cake batter.

Scrape the batter into the cake pan. Bake for 20 to 25 minutes, until it bounces back when gently pressed and a toothpick inserted in the center comes out clean. Remove from the oven and let cool fully before assembly.

To make the marshmallow frosting, add the egg whites and cream of tartar to a large bowl (where you’ll whip with a whisk or hand mixer) or a stand mixer with the whisk attachment. Beat until stiff peaks form. Be patient, as this may take some time. Add the salt and vanilla and mix thoroughly.

In a small saucepan, combine the ¾ cup of sugar with ¼ cup of water, then brush down the sides with a wet pastry brush. Over medium heat, bring the mixture to 235°F. Once the sugar syrup reaches the correct temperature, remove from the heat and slowly drizzle into the meringue while mixing. The frosting will thicken from the hot sugar and take on a lacquered finish.

To make the chocolate glaze, add all of the ingredients to a double boiler. Melt and mix until fully homogenized. Let cool to 90°F before coating the cake.

To assemble, remove the cake from the pan and remove the parchment from the bottom. Using a large serrated knife, cut the cake in half horizontally. Dab a little chocolate glaze on the bottom of the plate to hold the cake in place. Place the bottom of the cake on the plate and dollop the marshmallow frosting evenly on top. Add the top of the cake and dollop the chocolate glaze on the top of the cake using an offset spatula to move it over the edges, coating the entire cake.