While these sound fairly complicated, I promise it's all very easy. If I, a sleep deprived mother of two very small children, can make them with only a few (fortuitous, it turns out) mistakes, then anyone can make them. In fact, I'll probably make them again sometime soon (because I have quite a bit of the curd left over) (and hopefully I'll remember to take a picture this time), and if I can turn them out in an even more sleep deprived state (I blame the baby and her growth spurt followed by a head cold) then really, really anyone can make them.
(And here's where you imagine a picture of a lightly yellow cake, filled with a delicately pink citrus curd, and topped with a cream colored frosting rose.)
2 large eggs, separated
1 3/4 c. sifted cake flour
2 tsp. baking powder
1/4 tsp. salt
1/2 c. room temperature butter
1 c. sugar, separated
1 tsp. vanilla extract
the zest of one lemon
1/2 c. milk
1/8 tsp. cream of tartar
Separate the eggs into two separate mixing bowls and let them come to room temperature.
Preheat your oven to 350 degrees F. Line cupcake tins with cupcake liners (or grease and flour tins if you'd prefer). The recipe made 12 cupcakes. (You could also use the batter to make a layer cake, using two 8- or 9-inch pans, and increasing the baking time a little.)
Sift flour, baking soda, and salt into a small bowl and set aside.
Using an electric mixer, beat the butter until soft and creamy. Add 3/4 c. of the sugar and beat until well combined. Add the egg yolks one at a time, mixing until completely incorporated. Add vanilla and lemon zest and mix until combined.
Add the flour mixture and milk, alternately, starting and ending with the flour mixture; mix until just combined and do not over beat.
In a separate clean bowl with a clean whisk attachment, whip egg whites until foamy and then add the cream of tartar. Beat until soft peaks occur. Gradually add in the remaining 1/4 c. sugar, beating until stiff peaks form. Fold egg whites into the cake batter with a rubber spatula until just combined.
Put batter into prepared cupcake tins and bake for 18-20 minutes. Cakes are done when you insert a toothpick and it comes out clean or with very few crumbs.
After a couple of minutes, remove the cupcakes from the tins and allow them to cool completely on a wire rack.
When the cupcakes are cool, create a well in the middle of the top of the cupcake using a melon baller or spoon. I used the large side of my melon baller. This is where you'll put the citrus curd.
Blood Orange Lemon Curd
Juice of one blood orange
Juice of one lemon
1/2 c. sugar
1 egg yolk
4 T. butter, cut into small chunks
Whisk together the blood orange juice, lemon juice, sugar, eggs and egg yolk in a large bowl. Place the bowl over a pot of simmering water to make a double boiler and add the butter. Whisk continuously until the mixture begins to thicken, about 10 minutes. Continue to gently stir the curd until it is thick, creamy, and can coat the back of a spoon completely (about 5 more minutes).
Transfer to a wide bowl or high-rimmed plate, and press a piece of plastic wrap to the surface. Place in the refrigerator to cool completely.
(Very Loosely) adapted from I Am Baker
1/2 c. butter
1/2 c. shortening
4 c. confectioner's sugar
1 Tbsp. lemon juice
3/4 c. heavy cream
In a large bowl, cream shortening with a mixer until fluffy. Add confectioner's sugar (2 c. at a time) until well blended. Add lemon juice and heavy cream and whip until frosting is light and fluffy.
TO ASSEMBLE CUPCAKES:
Place 1 Tbsp. lemon curd (more or less depending on the size of the well you made) in the well you made in the cupcake. Top with a large dollop of buttercream to cover the well, or pipe on frosting in the manner of your choosing (I used a large star tip to make frosting roses). Chill until ready to serve.
Phew, that was a long one. It took almost as long to write this as it did to make the cupcakes! If you do make these, prepare to bathe in the glorious comments you receive from those who eat them. My coworkers said they felt like these came from some sort of cupcake boutique where you would pay $6 per cupcake; quite the complement!