Key Lime Cupcakes with White Chocolate Rum Ganache Filling

The most popular post in the history of this blog is my recipe for Buttery Nipple Cupcakes with Butterscotch Schnapps Ganache Filling. It's one of my favorites but has a definite Fall vibe. After a lot of tinkering around, I've come up with another cocktail turned cupcake recipe. I think it will be a Spring favorite, with Key Lime Pie, Coconut Rum, and White Chocolate flavors. What could go wrong with that combo?

Enjoy!

Key Lime Cake Base

2 sticks (8 ounces) unsalted butter, at room temperature

1 1/2 cups granulated sugar

4 large eggs

1 teaspoon vanilla extract

3 cups all-purpose flour

1 teaspoon baking powder

1/2 teaspoon finely grated lime zest

1/2 teaspoon salt

1 cup milk

Preheat the oven to 350 degrees and line one 12-cup muffin tin with cupcake liners.

Cream the butter in a large bowl with an electric mixer until smooth. Gradually add the granulated sugar and beat until light and fluffy, about 3 minutes. Add the eggs, one at a time, scraping down the sides of the bowl between additions. Beat in the vanilla.

Combine the flour, baking powder, lime zest and salt in a medium bowl. Add one-third of the flour mixture to the butter mixture; beat in half the milk. Repeat additions, ending with the flour. Beat until combined, but don't overmix!

Divide the batter between the prepared muffin tins, filling the cups two-thirds full. Bake until a toothpick inserted into the center of the cupcakes comes out clean and the tops spring back when pressed gently, about 18 to 22 minutes. Cool the cupcakes in the tins on a rack for 10 minutes, and then remove from the tins and cool completely.

Rum and White Chocolate Ganache Filling

6 oz. white chocolate morsels

6 Tbsp heavy whipping cream

3 Tbsp unsalted butter

1.5 oz Coconut Rum

In a small saucepan, heat cream and butter until just before the boiling stage. Remove from heat. 

Pour in the Coconut Rum and stir until combined . 

Pour the cream mixture over the white chocolate morsels, in a separate bowl. Let stand about 20 seconds, then stir until smooth.

Prepare the cupcakes for filling. An apple corer is a perfect tool for the job. Fill em up!

Key Lime Buttercream Frosting:
4 - 5 cups confections sugar
2 sticks (1 cup or 8 ounces) unsalted butter, at room temperature
1 tsp Vanilla Extract
3 tsp Key Lime Juice
2 Tbsp Key Lime Zest
3 tsp Coconut Rum

Whip the butter using an electric or hand mixer for several minutes. You want the butter to look almost white and be very light and fluffy.

Slowly add the powdered sugar, a few tablespoons at a time. 

When the frosting is thick, drizzle in the Key Lime Juice and Coconut Rum. Whip until combined. If the frosting is too thin at this point, add another spoonful or two of powdered sugar. Gently stir in the Key Lime Zest.

Pipe onto the cupcakes. If you're planning to spread the icing, you can cut the frosting recipe in half. You won't need as much.

Enjoy!