Essentially, I took the recipe for the Cola Cake and the Rum Cake and I merged them together to form my first attempt. I may or may not make alterations in the future.
Ingredients for the cake:
3 cups ap flour sifted
1 tbsp cornstarch
1 cups sugar
2 sticks butter
3 tbsp cocoa powder
1 1/4 cup Coca Cola
1/4 cup grenadine
1 tbspn buttermilk powder
1 tsp baking soda
1/2 tsp baking powder
2 tbsp vanilla
1 mini bottle Myer's dark rum
2 c. miniature marshmallows
Preheat oven to 350˚F
Grease and flour two round cake pans
Sift the dry ingredients into a bowl and set aside.
In a small saucepan bring the butter, Cola and grenadine to a boil, set aside to cool for a few minutes.
Meanwhile break the eggs into a large bowl, and beat slightly. Add the vanilla and the rum and stir. Add the butter/cola/grenadine mixture. Mix well.
Whisk in the dry ingredients, slowly adding more. Mixture should be around the consistency of (boxed) brownie batter. Stir in the marshmallows.
Pour batter into prepared pans (marshmallows will float to top and caramelize while baking) and bake for 15-20 minutes or until a toothpick comes out clean.
Remove from oven and let cool in pans.
Cola Buttercream (the hard way, lol)
1/3 cup coca cola
2 sticks unsalted butter, softened
2 tbsp grenadine
2 tbsp dark rum
2 tbsp vanilla extract
3 tbsp cocoa powder
1 tbsp pomegranate liqueur (available in mini-bottles at Bev-Mo) (optional)
About 2 lbs powdered sugar
1 cup almond meal (optional)
pinch of salt
In a mixer fitted with the whisk attachment beat the butter until smooth.
Sift in the cocoa powder and a little bit of powdered sugar.
Slowly add the liquid ingredients, alternating with powdered sugar (sifted in) and the almond meal. Add salt to taste.
Only add as much powdered sugar as will make the buttercream stiff enough for your usage. If using it more like a glaze, then only add as much powdered sugar as will make the buttercream not look curdled.
I garnished the cake with maraschino cherries sans stems for a simple presentation, but I didn't have the opportunity to photograph.