Happy Spring! It’s Spring … right? Well, to celebrate the slow start of Spring in the Mid-Atlantic, I decided to craft a pink grapefruit cupcake recipe for today. I really enjoy grapefruit juice, and have wanted to make a grapefruit cupcake for ages. I even purchased a natural grapefruit extract to help me punch up the flavor.
Citrus curds are also one of my favorite things to make … and eat. I hunted around a bit to find a good grapefruit curd recipe, because I didn’t think switching in grapefruit juice for lemon juice would be wise (I wasn’t sure how sour it would be). I found the following recipe on Serious Eats—I halved it, and skipped the vanilla, and am pretty pleased with the outcome.
I thought about making a honey buttercream, but I know in the past the flavors have been very bold (which is nice). Because this was my first time working with grapefruit, I didn’t want to overshadow it with honey, hence the triple grapefruit combo of cake, filling and frosting.
Make the grapefruit curd first so it has time to set.
In a large metal mixing bowl, massage the zest into the sugar with a large spoon (or your hands!) until fragrant.
Whisk in the eggs and egg yolks.
Place the bowl over a pot of simmering water to make a bain marie and clip a candy thermometer to the side of the bowl.
Stir the curd for approximately 30 seconds until the sugar dissolves. Add the grapefruit and lemon juices.
Stir the curd continually for 12-15 minutes until it reaches roughly 170-180 degrees Fahrenheit on the thermometer.
Take the curd off the heat, and position a fine mesh sieve over a bowl.
Pour the curd through the sieve, using a flexible spatula to press it through, holding back the zest and any cooked egg. Discard.
Add the butter and stir until melted.
Let the curd cool and refrigerate until ready to serve. [Please note: this curd must be refrigerated ... it is not shelf stable].
For the cupcakes, heat the oven to 350 degrees Fahrenheit and position the racks toward the center. Line pans with cupcake papers.
Combine the flour, baking powder, and salt in a bowl and gently mix to combine. Set aside.
Add the grapefruit zest to the sugar and stir until fragrant. Add the butter.
Cream the butter with the sugar, beating until light and fluffy.
Add the eggs one at a time, mixing to combine.
Alternate the dry ingredients and milk, and mix until combined.
Add the grapefruit extract.
Divide the batter between 24 wrappers in the cupcake tins and bake for 20-24 minutes.
Cool completely before coring and filling with grapefruit curd.
For the frosting, beat the butter until light and fluffy. Add a 1/2 cup of confectioners sugar and mix to combine.
Add the grapefruit extract, and gradually add the remaining confectioners sugar. Whip until light and fluffy. Add the milk if the texture needs to be evened out.
Fit a bag with an extra large star tip and pipe the frosting on top of the cored and filled cupcakes.