Key Lime Cupcakes with Lime Curd

Directions

1. Cupcakes
2. Preheat oven to 325°F. Line a standard muffin tin with paper liners. Whisk together flour and salt.
3. In a small bowl mix together graham cracker crumbs, 2 tablespoons of sugar, and butter. Set aside.
4. With an electric mixer on medium-high speed, cream butter and 2/3 cup sugar until pale and fluffy, scraping down sides of bowl every few minutes. Add lime zest. Reduce speed to medium, and add vanilla. Add eggs, one at a time, beating until until incorporated, scraping down sides of bowl as needed. Reduce speed to low. Add flour mixture in four batches, beating until completely incorporated after each.
5. Place 1 tablespoon graham cracker mixture into the bottom of each prepared muffin cup. Use the bottom of a small glass to pack crumbs into the bottom of each cupcake liner. Reserve remaining graham cracker mixture for topping.
6. Transfer muffin tins to oven and bake until the edges of the graham cracker mixture is golden, about 8 minutes. Remove from oven and fill each muffin cup three-quarters full with cake batter; tap pan on counter-top once to distribute batter. Sprinkle each with remaining graham cracker mixture trying to avoid sprinkling over the center of each muffin as they will scooped out.
7. Bake, rotating tin halfway through, until a cake tester inserted in centers comes out clean, about 20 minutes. Transfer tin to wire racks to cool 10 minutes; turn out cupcakes onto racks and let cool completely. Cupcakes can be stored up to 2 days refrigerator, in an airtight container.
8. ?To assemble the cupcakes, use a paring knife to cut out a cone shape out of the center of each cupcake the size of a quarter.
9. ?Remove chilled lime curd from the refrigerator and stir to loosen. Place curd in a squeeze bottle or pipping bag to ease filling the center of each cupcake. Fill each cupcake just to the top.
10. Transfer frosting to a large pastry bag fitted with a large French tip (such as Ateco #844). Pipe frosting in a spiral motion on each cupcake, just large enough to cover the lime curd without covering the surface of the entire cupcake. Transfer cupcakes to a baking sheet. Using a kitchen torch, lightly brown the frosting, taking care not to burn the cupcake liners. Serve immediately or store refrigerated in an airtight container, up to 2 days.

1. Lime Curd
2. Place sugar and lime zest in a mortar and grind with a pestle to combine and release the oils. Transfer sugar mixture to a medium heatproof bowl along with eggs and egg yolks; whisk to combine. Place over a saucepan of simmering water and whisk until sugar has dissolved. Add lemon juice and continue whisking until mixture is thick and reaches 160°F on an instant-read thermometer, scraping down sides of bowl as necessary. Add butter and whisk until well combined.
3. Pour lime curd into a clean medium bowl. Cover lime curd with plastic wrap, pressing plastic wrap directly onto surface. Transfer to refrigerator until completely chilled.
4. Marshmallow Topping:
   2 large egg whites
   1/2 cup sugar
   1/4 teaspoon cream of tartar
5. Place egg whites, sugar, and cream of tartar in the heatproof bowl of an electric mixer. Set over a saucepan with simmering water. Whisk constantly until sugar is dissolved and whites are warm to the touch, 3 to 4 minutes.
6. Transfer bowl to electric mixer fitted with the whisk attachment, and beat, starting on low speed, gradually increasing to high, until stiff, glossy peaks form, 5 to 7 minutes. Add vanilla, and mix until combined. Use immediately.