Candied Grapefruit Cupcakes

Ingredients

• 1 red grapefruit
• 3 tablespoons elderflower liqueur (such as St-Germain)
• 1/2 cup granulated sugar
• 1 1/2 cups all-purpose flour
• 1 1/2 teaspoons baking powder
• 1/4 teaspoon salt
• 1 stick unsalted butter
• at room temperature
• 1 cup granulated sugar
• 2 large eggs
• at room temperature
• 1 teaspoon vanilla extract
• 1 tablespoon finely grated red grapefruit zest
• 1/2 cup milk
• 1 stick unsalted butter
• at room temperature
• 3 cups confectioners sugar", "2 drops red food coloring (optional)", "1 tablespoon finely grated red grapefruit zest, plus segments for topping", "2 tablespoons elderflower liqueur (such as St-Germain)

Instructions

1. Make the candied zest: Remove the grapefruit zest with a vegetable peeler and slice into thin strands.
2. Place in a saucepan; cover with water and bring to a simmer.
3. Drain the zest and return to the saucepan; cover with water and repeat 2 more times.
4. Set the zest aside.
5. Juice the grapefruit into the saucepan, reserving 1 tablespoon for the frosting.
6. Add the liqueur and granulated sugar; bring to a simmer over medium-high heat, stirring to dissolve the sugar.
7. Add the zest, reduce the heat to low and simmer 20 minutes.
8. Remove with a slotted spoon; set aside.
9. Reserve the syrup.
10. Make the cupcakes: Preheat the oven to 350 degrees F and line a muffin pan with 12 cupcake liners.
11. Whisk the flour, baking powder and salt in a medium bowl.
12. Beat the butter and granulated sugar in a large bowl with a mixer on medium-high speed until light and fluffy, about 5 minutes.
13. Beat in the eggs, one at a time, then beat in the vanilla and the grated grapefruit zest.
14. Reduce the speed to medium and add the flour mixture in 3 additions, alternating with the milk, beginning and ending with the flour mixture; beat until the batter just comes together.
15. Divide the batter among the muffin cups, filling each two-thirds of the way.
16. Bake until a toothpick inserted into the centers comes out clean, 18 minutes.
17. Poke a few holes in each cupcake with a toothpick.
18. Reheat the grapefruit syrup; brush generously over the cupcakes (reserve the remaining syrup).
19. Remove the cupcakes to a rack to cool completely.
20. Make the frosting: Beat the butter in a large bowl with a mixer on medium-high speed until fluffy, about 2 minutes.
21. Add the confectioners' sugar, food coloring, grated grapefruit zest, liqueur and the reserved 1 tablespoon grapefruit juice; beat until smooth, about 3 minutes.
22. Spread the frosting on the cupcakes.
23. Dip grapefruit segments in the remaining syrup and set on the cupcakes; top with the candied zest.