Will Cook For Friends: Rum and Coke Cupcakes

Rum and Coke Cupcakes, with Rum and Coke Swiss Meringue Buttercream and Rum Spiked Caramel Sauce - recipe in post

Happy birthday to you! Happy birthday to you! Happy birthday dear Brother... Happy birthday to you!

As an outsider, downtown Pittsburgh is nothing short of a nightmare to navigate - in some areas, the ramps and bridges twist and bend like something out of an Escher drawing - but from the passenger's seat of my brother's car, the city is actually quite beautiful. Especially at night, the hillsides filled with lights shining down on the river, and the old architecture everywhere you look.

For The Brother's birthday, I made the trip from Michigan to Pennsylvania for the first time since, well, last year. Wow, really? We're just about as close as two siblings can be, but we live two very different lives, in two very different places... so when it came to getting something for him, I was a little stumped. What does he like, what would he want? I hadn't a clue.

The Brother in his Birthday Throne

Thankfully, a little birdy told me one of his favorite drinks is a rum and coke... and, more precisely, The Kraken black spiced rum. This was less than a week before his birthday, so with very little time to prepare, I decided to make him some Rum and Coke cupcakes. And a Kraken cupcake stand for presentation. That seems easy enough, right?

In old Norse myth, The Kraken was a legendary sea monster of leviathan proportions, lurking in the depths of the ocean and monstrous enough to take down entire ships in a single gulp. Presumably based on sightings of real giant squid, no one suspected that the wrath of these fierce creatures might be quelled by… cupcakes?

Let me start by saying - air dry clay, never again. That stuff is not designed for a sculpture of this magnitude. As the clay dried, it cracked and crumbled, and I was left to constantly patch the gaps and cracks. Still, I somehow managed to finish the cephalopod sea-creature just in time. Nearly ten pounds of clay later (and several wire coat hangers for support) my creation was complete. It even managed to hold the cupcakes, and a bottle of rum and coke, without collapsing!

From these angles you can see some of the wire supports

The really impressive thing, though, is that after taking some photos the whole thing made the trip to Pittsburgh in the back of my car with very little breakage. Success!

Loading it into the back seat... buckle up, Kraken!

All set up to surprise The Brother - I'm stoked!

The Brother was thoroughly impressed and surprised. His first course of action was to take the coke from The Kraken's grasp and pour in a shot of rum.

Then it was on to some cupcakes. Cheers!

As impressive as the presentation was, these cupcakes were still the star of the show. I spent an entire day testing recipes - five batches of cupcakes and half a bottle of rum later, I finally came up with something I liked.

I started by trying recipes for rum cake, and adding coke... then coke cake, and adding rum... then a couple recipes specifically for rum and coke cake... but none of them were what I wanted. Finally I started winging it on my own, using pieces of recipes I liked and franken-mashing them together into something truly amazing.

These cupcakes would be perfect for a 21st birthday celebration!

These are possibly some of the best cupcakes I've made. The coke flavor isn't very prominent, and if you were to eat one without being told you probably wouldn't say "rum and coke" right away - but once you know, you get it. The cake is lightly spiced, with a bit of lime, and the buttercream is rich with lots of rum and just a touch of brown sugar. The drizzle of rum spiked caramel sauce is just the cherry on top of an already delicious treat, and the recipe makes just enough for a little extra, perfect for drizzling over ice cream or dipping fruit slices.

I'm not a big drinker, but I have to say I'm quite proud of this recipe. It was hard not to eat all the cupcakes before they made it to Pittsburgh... willpower, that is my gift to you, Brother!

Recipe Notes: I used The Kraken black spiced rum for this recipe, and loved the smooth, sweet flavor. If you're using a different kind of rum you may want to reduce the amounts slightly (replace with more coke) depending on how harsh the flavor is. I suggest using a dark, high-quality alcohol for this recipe.
I made half of my cupcakes gluten-free, using my gluten-free flour blend (click for recipe). I replaced the flour one for one, and the cupcakes turned out perfectly!

Rum and Coke Cupcakes
Makes 18-20 cupcakes

2 cups (260g.) all-purpose flour (or gluten-free flour blend)
1 1/4 tsp. baking powder
1/2 tsp. baking soda
1/2 tsp. salt
1/2 tsp. unsweetened cocoa powder
1/4 tsp. ground allspice
1 1/4 cups granulated sugar
1/2 cup (1 stick) unsalted butter, softened
1 tsp. lime zest (about 1 lime)
2 large eggs, room temperature
1 cup coca-cola (regular, not diet)
1/4 cup + 2 TBSP dark spiced rum (such as The Kraken)
1 TBSP lime juice (about 1 lime)
1 tsp. vanilla extract

For brushing:
4 TBSP coca-cola
2-3 TBSP dark spiced rum

Method
Preheat oven to 350f., and line a couple cupcake pans with liners. Set aside.
Whisk together flour, baking powder, baking soda, salt, cocoa powder, and allspice. Set aside.
Cream together butter, sugar, and lime zest until smooth and fluffy, about 3 minutes. Add the eggs one at a time, beating well after each addition.
On low speed, add in the cola, rum, lime juice, and vanilla extract - the mixture will curdle and look very unappetizing, but that's okay.
Fold the wet mixture into the dry ingredients until just combined. Scoop into liners, filling about 2/3-3/4 of the way full.
Bake on the center rack for 13-15 minutes, or until springy on top and a tooth pic comes out clean.
Remove from the oven and let cool in the pan for 2-3 minutes. Brush tops with rum and coke mixture - be generous and go over them more than once - then transfer to a wire rack to finish cooling. Top with frosting and caramel sauce (recipe follows).

Rum and Coke Swiss Meringue Buttercream
Makes enough to frost about 40 cupcakes, or two batches

1/2 cup egg whites, room temperature (about 100g., or 3 large eggs)
3/4 cup (about 175g.) granulated sugar
1/4 cup (about 55g.) light brown sugar, packed
1 1/4 cups (2 1/2 sticks) unsalted butter, room temperature and cut into cubes
1/4 tsp. salt
1/2 cup coca-cola (regular, not diet
3-5 TBSP rum, or to taste (I may have spilled a little extra in, you know, accidentally)*

*The amount of rum you need may vary depending on the brand you use. I was able to add quite a lot, because The Kraken is so sweet and smooth.

Method
In a small pot, place the coca-cola over medium-low heat until reduced to about 3-4 tablespoons. Set aside to cool to room temperature.
Thoroughly clean a large metal bowl, or the bowl of your stand mixer, and your beaters or whisk attachment. Wipe your bowl and utensils with a bit of vinegar or lemon juice to ensure no grease remains.
Set a small pot of water over medium heat, and bring to a gentle simmer.
In your bowl, combine the egg whites, sugars, and salt. Place over the pot of hot water and whisk gently but constantly until the sugar has dissolved, and the mixture reaches 145-150f.
Remove the bowl from over the pot, and begin mixing on high until white, fluffy, and cooled to room temperature.
Add the butter a few tablespoons at a time, beating constantly. Once all of the butter is added, your mixture may appear sloppy or curdled - this is normal, the frosting is not ruined! - keep beating. Continue mixing, stopping to scrape down the sides from time to time, until the buttercream becomes smooth and luscious.
Add the reduced coke, and rum to taste.

Swiss Meringue Buttercream can be made up to a week ahead, and stored in an airtight container in the fridge. When ready to use, bring to room temperature on the counter and then re-whip until smooth and fluffy. For a good step-by-step photo tutorial for Swiss Meringue Buttercream (it can be tricky if you've never made it before and don't know what it looks like) check out Sweetapolita's post, here.

Rum Spiked Salted Caramel Sauce
Makes about 1/2 cup

1/3 cup granulated sugar
1 1/2 TBSP water
1 tsp. light corn syrup, or brown rice syrup
5 TBSP heavy cream
1/2 TBSP unsalted butter
1-3 TBSP dark spiced rum
1/2 tsp. vanilla extract
Fleur de Sel, to taste (or sea salt)

Method
In a small sauce pan over medium heat, add the sugar, water, and corn syrup. Stir until the sugar dissolves, then increase heat to a boil. Cook, without stirring, until the syrup darkens to a deep amber color - the mixture will froth and bubble, so give the pan a swirl every once and a while to see it better and keep it from scorching.
Remove from heat, and add the cream and butter - the mixture will bubble vigorously. Add the rum, vanilla, and a pinch of salt. Cool slightly before tasting, and adjusting the salt as needed.
Let cool completely before drizzling over the cupcakes (if the caramel is hot it will melt the butter in the frosting). If the caramel becomes to stiff to drizzle, rewarm it slightly and stir in a little more cream.