How to Make Buttermilk-Lime Cupcakes with Swiss Meringue Buttercream Frosting

Yields: 12 servings | Prep Time: 30 minutes | Total Time: 1 hour 25 minutes
Any spring celebration would be ideal for these little lilac-colored cupcakes. Their fresh buttermilk and lime taste will astonish your guests!
Ingredients:
For the cupcakes:
- 6 Tbsp. (3/4 stick) unsalted butter, at room temperature
- 1/4 cup solid virgin coconut oil
- 3/4 cup granulated sugar
- 3/4 tsp. baking powder
- 1/4 tsp. baking soda
- 1/4 tsp. kosher salt
- 3 large egg whites, at room temperature
- 2 tsp. pure vanilla extract
- 1 1/2 cups cake flour, spooned and leveled, and sifted
- 2/3 cup whole buttermilk, at room temperature
- 1 Tbsp. grated lime zest, plus 1/4 cup lime juice
For the buttercream frosting:
- 1 cup granulated sugar
- 3 large egg whites
- 1 1/2 cups (3 sticks) unsalted butter, cut into pieces, at cool room temperature
- 1 Tbsp. pure vanilla extract
- 1/4 tsp. kosher salt
- Purple, pink, and blue gel food coloring
Instructions:
STEP 1: Turn oven to 325°F. Lay paper liners in a regular 12-cup muffin tray.
STEP 2:
- Using an electric mixer on low speed, beat butter, coconut oil, sugar, baking powder, baking soda, and salt until mixed, roughly one minute.
- Scrape down sides as needed; increase speed to medium and beat until light and fluffy, 4 to 6 minutes.
- One at a time, add egg whites until blended.
- Vanilla's beat is simple.
- Starting and finishing with flour mixture, alternate adding buttermilk and flour. Till combined, mix.
- Add juice and lime zest.
- Spoon the batter equally among the muffin cups.
- Bake until a toothpick put into center comes out clean, 20 to 23 minutes.
- Cool totally on a wire rack.
STEP 3: Regarding the buttercream Frosting
- In a medium sauté pan, bring one inch of water to a simmer.
- Whirl sugar and egg whites in a bowl. Make sure the bowl stays above the simmering water such that it does not come into touch. Stirring will help the sugar dissolve and the mixture will reach 160°F.
- About 9 to 10 minutes, whisk in an electric mixer on medium-high speed until frothy and glossy.
- Gradually add the butter, one tablespoon at a time, mixing until blended, slowing the mixer speed to medium.
- Beat vanilla and salt separately.
STEP 4: Spoon the buttercream into three bowls and dye each purple, pink, and blue gel food coloring.
STEP 5: Spoon the colors into a big piping bag designed for 2D tips. To barely mix the colors, gently squeeze the bag. Beginning in the middle of every cupcake, pipe little flowers all across the top. Proceed with all of the cupcakes.