Who said that the only way to enjoy Key Limes were in a Key Lime pie? These cupcakes are a delicious way to enjoy those special limes. You will get rave reviews!
lime curd:
1/2 c. granulated sugar
1 large egg + 1 egg yolk
1/4 c. fresh Key lime juice (from about 8 Key limes)
2 t. cornstarch
4 T. unsalted butter, cut into pieces
1 t. grated Key lime zest (from about 2 Key limes)
pinch of salt
cupcakes:
12 chocolate wafer cookies
12 tablespoons unsalted butter, at room temperature
1 1/4 c. all-purpose flour
1/2 t. baking powder
1/4 t. baking soda
1/4 t. salt
3/4 c. granulated sugar
2 large eggs, at room temperature
1 t. vanilla extract
1 t. grated Key lime zest
2 T. fresh Key lime juice (from about 4 Key limes)
1/3 c. buttermilk
frosting:
1 stick unsalted butter, at room temperature
3 1/4 c. confectioners' sugar
1/4 c. sour cream
1 T. fresh Key lime juice
pinch of salt
Key lime slices and grated zest, for topping
Lime curd:
Combine the granulated sugar, egg and egg yolk, lime juice and cornstarch in a small saucepan. Cook over medium-low heat, whisking, until thick enough to coat a spoon, 8 - 10 minutes. Remove from heat; whisk in the butter, a little at a time, until smooth. Strain through a fine-mesh sieve into a bowl; stir in the lime zest and salt. Set bowl in a larger bowl of ice; stir until curd is completely cool. Press plastic wrap directly onto the surface; refrigerate until ready to use.
Cupcakes:
Preheat oven to 350 degrees; line muffin pans with 12 cupcake liners. Pulse wafer cookies in a food processor until finely ground. Melt 2 tablespoons butter; add to the processor; pulse until the mixture comes together. Press about 1 tablespoon crumbs into each muffin cup.
Sift flour, baking powder, baking soda and salt into a medium bowl; set aside. Combine remaining 10 tablespoons butter and the granulated sugar in a large bowl; beat with a mixer on medium-high speed until fluffy, 5 minutes. Reduce the speed to low; beat in the eggs, one at a time; add vanilla, lime zest and juice; beat until well-combined. Add the flour mixture in 3 additions, alternating with the buttermilk, beginning and ending with the flour mixture. Increase the speed to medium-high; mix until combined.
Divide batter among the prepared muffin cups, filling each about three-quarters of the way. Bake until a toothpick inserted into the centers comes out clean, 20 to 22 minutes. Remove to a rack; let cool completely.
Frosting:
Beat butter in a large bowl with a mixer on medium-high speed until fluffy, 5 minutes. Reduce speed to low; beat in the confectioners' sugar. Increase speed to medium-high; add the sour cream, lime juice and salt; beat until fluffy, 2 minutes.
Place lime curd in a pastry bag fitted with a 1/4-inch tip. Insert tip into the center of each cupcake and squeeze to fill. Frost the cupcakes, then pipe more lime curd on top. Top with lime slices and zest to garnish.
**Key limes are smaller and more tart than regular limes. Use bottled Key lime juice and use regular lime zest, if you can't find Key limes.