Spiced Eggnog Cupcakes with Vanilla-Rum Swiss Buttercream
adapted from Magnolia Bakery ^[5] and Martha Stewart ^[9]

Ingredients:

For the cupcakes:

• 1 1/2 cups self-rising flour
• 1 1/4 cups all-purpose flour
• 1 teaspoon ground cinnamon
• 1/2 teaspoon ground nutmeg
• 1 cup (2 sticks) unsalted butter, softened
• 2 cups sugar
• 4 large eggs, at room temperature
• 1 cup eggnog
• 2 tablespoons dark rum (or 1 teaspoon rum extract)
• 1 teaspoon vanilla extract

For the buttercream:

• 5 large egg whites, room temperature
• 1 cup plus 2 tablespoons sugar
• Pinch of salt
• 1 pound (4 sticks) unsalted butter, at room temperature and cut into tablespoon-sized cubes
• 2 teaspoons vanilla extract
• 1-2 tablespoons dark or spiced rum to taste (optional)

Directions

1. To make the cupcakes: Preheat oven to 350 F. Line 2 standard-sized muffin tins with cupcake papers and set aside.
2. In a small bowl, whisk together the flours, cinnamon and nutmeg. Combine the rum and vanilla together in a small cup or bowl. Set both aside.
3. In a large bowl, cream the butter with an electric mixer or stand mixer until smooth. Add the sugar and beat on medium-high until light and fluffy, about 3 minutes. Turn the mixer down to medium-low and add the eggs, 1 at a time, beating well after each addition.
4. Add the dry ingredients in 3 parts, alternating with the eggnog and rum/vanilla mixture. With each addition, beat just until the ingredients are incorporated. Scrape down the batter with a rubber spatula, as needed, to make sure the ingredients are well blended. Using a medium-sized ice cream scoop, carefully fill each cupcake liner about 3/4 full. Bake for 20 to 25 minutes, or until a cake tester inserted into the center of a cupcake comes out clean.
5. Cool the cupcakes in the tins for 15 minutes. Remove from the tins and cool completely on a wire rack before icing.
6. To make the buttercream: Combine egg whites, sugar, and salt in the heatproof bowl of a standing mixer set over a pan of simmering water. Whisk constantly by hand until mixture is warm to the touch and the sugar has completely dissolved. The temperature on an instant-read thermometer should read160 F.
7. Attach the bowl to a stand mixer fitted with the whisk attachment. Starting on low speed, and gradually increasing to medium-high speed, whisk until the mixture is thick and glossy, and has come down to room temperature. (Test by touching the bottom of the bowl. It should not still feel warm.) This should take about 10 -12 minutes, but can take as long as 15.
8. Switch over to the flat beater of your stand mixer and decrease the speed to medium-low. Add the butter cubes, a few cubes at a time, mixing continuously until you have added all of the butter and the buttercream is very silky and smooth. Scrape down sides of bowl with a rubber spatula as needed. Add the vanilla and rum and mix until combined. If the buttercream curdles, keep beating and it should come back. Keep buttercream at room temperature if using the same day. If not using it on the same day, store the buttercream in an airtight container in the fridge for up to one week. When ready to use, let it come to room temperature and re-whip it for about 5 minutes, until it is satiny smooth again.
9. Pipe or slather some frosting onto each cupcake before serving. Decorate with sprinkles, if desired.

Makes 24 cupcakes.