For the cupcakes: Preheat the oven to 325 degrees F. Line a standard cupcake pan with 12 cupcake liners.
Sift the sugar, flour, cocoa, baking soda, and salt into a medium bowl. Set the bowl aside. In a small bowl, whisk together the seltzer water, coffee, oil, and vanilla. Add the wet ingredients to the dry ingredients and whisk until just incorporated. Add the vinegar and incorporate. Do not over mix the batter.
Fill the cupcake liners 3/4 full and bake until a toothpick inserted into each cupcake comes out clean, 19 minutes. Cool the cupcakes completely.
For the ganache: Heat the soy creamer in a double boiler over medium heat until steaming. Do not boil. In a separate bowl, pour the hot creamer over the chocolate and let sit for 30 seconds. Whisk the soy creamer and chocolate until the chocolate is melted and the 2 ingredients are completely combined. The ganache should be thick, but still pourable. Set aside.
For the frosting: In the bowl of a stand mixer, whip the shortening, margarine, and banana compound. Scrape the bottom of the bowl to ensure that all ingredients are mixed thoroughly. On low speed, slowly add the sugar a little at a time. Once the sugar is incorporated, mix on medium-high speed until all the ingredients are combined and the frosting is fluffy, about 2 minutes. Drop the whole banana into the frosting and let it mix for an additional 2 minutes, or until the banana is mashed. On low speed, add in the soy milk until incorporated, a little at a time until desired consistency is reached. Put the frosting into a pastry bag and cut 1/2 inch off the tip.
In a small saucepan, melt the brown sugar and margarine on medium heat. When the sugar crystals are completely dissolved in the melted margarine, add the rum and mix. Add the sliced bananas and stir gently. Let it come to a boil and thicken to desired texture. Remove from the heat and let cool.
To assemble: Dip the tops of each cupcake into the ganache so that the entire cupcake top is covered. Set aside for 10 minutes to allow the ganache to set on the cupcake. Pipe a dollop of banana frosting on top of each cupcake and garnish the top with 2 slices caramelized bananas.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.