Step 1: Preheat your oven to 350°F (175°C) and grease two 9-inch round cake pans. In one bowl, whisk together the dry ingredients: gluten-free flour, cocoa powder, baking soda, baking powder, and sugar. In a separate bowl, mix together the wet ingredients: oil, non-dairy milk, and aquafaba. Combine the wet and dry ingredients until just mixed, then pour the batter into prepared pans and bake for 30-35 minutes, or until the cake springs back when lightly pressed.

Step 2: While the cakes are baking, prepare your homemade graham crackers. In a mixing bowl, combine gluten-free flour, sugar, and softened vegan butter until crumbly. Add a splash of non-dairy milk to form a dough. Roll the dough out to about 1/8 inch thick, cut into squares, and place them on a baking sheet. Bake at 350°F (175°C) for 10-12 minutes until golden brown and aromatic. Allow them to cool completely.

Step 3: In a large mixing bowl, use an electric mixer to beat the vegan butter on high speed until light and fluffy, around 3-5 minutes. Gradually incorporate powdered sugar and add cocoa powder for chocolate buttercream or vanilla extract for a classic version. Mix until fully combined and fluffy. If the frosting is too thick, add a splash of non-dairy milk to achieve a smooth consistency.

Step 4: In a large, clean bowl, whip the aquafaba with an electric mixer until soft peaks form, which will take about 5-10 minutes. Gradually add granulated sugar and continue to whip until stiff peaks form, about 3-5 more minutes.

Step 5: Once your chocolate cakes are completely cooled, place one layer on a cake board or serving plate. Generously spread a layer of buttercream mixed with crushed graham crackers on top. Add the second layer of cake, repeating the filling process. Once assembled, apply a thin crumb coat of buttercream around the entire cake. Chill the cake in the refrigerator for about 30 minutes to set.

Step 6: After chilling, cover the cake with a smooth layer of chocolate buttercream, making it look as luscious as possible. Drizzle warm vegan chocolate ganache over the top, allowing it to drip down the sides. Spoon the whipped aquafaba meringue on top and carefully use a kitchen torch to lightly toast it until golden. Sprinkle extra graham cracker crumbs on top for added texture.