Delicious vanilla cupcake with a graham cracker base, filled with key lime curd, topped with light key lime buttercream, and a candied lime on top.
Course Dessert
Cuisine American
Keyword cupcakes, key lime, key lime pie
Prep Time 2 hourshours
Cook Time 1 hourhour
Decorating Time 1 hourhour
Total Time 4 hourshours
Servings 36cupcakes
Ingredients
Graham Cracker Crust
1½sleevesgraham crackers, crushed
6tbspbutter, melted
⅓cupsugar
1tspsalt
Vanilla Cupcakes
2½cupsall-purpose flour
2tspbaking powder
1tspbaking soda
2cupswhite sugar
¾cupsbutter, room temp
2largeeggs, room temp
2tspvanilla
2cupmilk, room temp
Key Lime Curd
¾cupwhite sugar
½cupkey lime juice
2tbsplime zest
5egg yolks
2tbspwater, cold
1pouchgelatin (approx. 2½ tsp)
¼cupbutter
Key Lime Buttercream
1½cupbutter, room temp
½cupshortening
7-8cupspowdered sugar
1tbsplime zest, plus more for garnish
3½tbspkey lime juice
½tspvanilla
Candied Limes
2limes, large
1cupsugar, plus more for dusting
1 cupwater
Instructions
Graham Cracker Crust
Line three muffin tins with paper cupcake liners, and preheat the oven to 350°F.
Place the graham crackers into a ziplock bag, and use a rolling pin to crush them into fine pieces. There shouldn't be any large chunks remaining.
In a mixing bowl, combine the graham cracker crumbs, melted butter, sugar, and salt. At first, the butter may stick to the crumbs in clumps, but keep stirring until the mixture is fully amalgamated. After a bit of mixing, it will resemble wet sand.
Using your handy bar muddler, press a large spoonful of crumbs into each lined well of the muffin tin. Tamp down well, creating a nice, solid graham cracker crust.
Bake the crusts for 7-8 minutes. They will be slightly golden brown when finished. Set aside and let cool while you prepare the cupcake batter.
Vanilla Cupcakes
Into a medium-sized bowl, sift the flour, baking powder, and baking soda. Set aside.
Beat the softened butter and sugar together on high for a few minutes, until the mixture is fluffy and light.
Into the bowl of your mixer, add the room temperature eggs and vanilla. Beat again until everything is combined.
Dump about a third of the flour mixture into the wet ingredients, and then pour in a third of the milk. Use a spatula to stir the batter until it just begins to come together. Repeat the process twice more, alternating between flour and milk. Stir carefully, distributing all the ingredients well, but taking care not to overmix the batter.
Using a quarter-cup sized measure, portion the batter evenly among the lined muffin tins. Remember, the graham cracker crust should be baked before adding the cupcake batter.
Place your cupcakes in the preheated oven (350°F) and bake for 28 minutes. Refrain from opening the oven prematurely, as letting the heat out can cause the cupcakes to deflate before forming enough structure to form a pretty domed top. When the timer is finished, use a toothpick to check for doneness. Moist crumbs are okay, but no wet batter should remain. If the cupcakes aren't fully cooked, let them bake for a few more minutes, testing again, before removing from the oven.
Let the cupcakes cool in their tins for about ten minutes, then gently release to a cooling rack. Let them fully cool before moving on to the next steps. If you need to store the cupcakes overnight, do so in a covered container at room temperature.
Key Lime Curd
Bring some water in a small pan to a simmer, and place your double boiler overtop.
Combine the sugar, lime juice, lime zest, and egg yolks in the double boiler, and whisk to dissolve the sugar. Continue stirring, constantly, until the temperature passes 140°F. This will ensure the egg yolks are properly cooked, and eliminate any chance of obtaining a food-borne illness. Then, continue stirring until the mixture starts to thicken, a few minutes more.
In a small bowl, add the cold water and pour in the gelatin. Let it sit for a few minutes to "bloom."
Remove the curd mixture from the heat and add in your butter and bloomed gelatin. Whisk everything together until the butter has melted and gelatin is fully dissolved.
Let this curd cool to room temperature, first, and then in the refrigerator. It will continue to thicken as the temperature drops.
Using a melon baller or cupcake corer, remove the centers of your cupcakes. Keep the scraps in a separate container - we don't waste any of the good stuff.
Next, add the cooled and thickened curd to a piping bag. Fill each cored cupcake center with the curd.
Then, press a scoop of cake back over the curd hole. These extra cake bits will likely bulge over the top of the rest of the cupcake, which is fine. When we pipe the buttercream, this extra domed shape will help add some pretty height to the icing.
Key Lime Buttercream
Add your softened butter and shortening to the bowl of your mixer and combine.
Slowly add powdered sugar to the butter, one cup at a time, mixing and scraping down the bowl in between each new addition.
To the buttercream, add in the lime juice and zest, as well as the vanilla. Mix well, and test the taste, adding more juice or vanilla if you'd prefer. This buttercream is best with a bright zing of key lime flavor, so don't hold back if you think it needs a bit more.
Next, insert a star or rosette tip of your choosing into a piping bag, and fill it with your delicious buttercream. In a circular motion, apply buttercream to the cupcake, starting at the outer edge, moving up and in with steady pressure on the bag.
Sprinkle on to the buttercream some extra lime zest for a zingy, finishing touch.
Candied Lime Slices
Start off by setting a pan of water on the stove to boil.
Cut the limes into thin slices, and then half or quarter each slice.
Drop the lime slices into your pan of boiling water. Let them cook for two minutes. Then, strain them into a bowl of ice-cold water, reserving the boiling water. If you accidentally strain out the water, it's okay - you'll just have to reboil another pot. :)
Stir the sugar back into the boiling water, and let it dissolve.
Then, add your lime slices into the simmering sugar water. Let them cook for about 15 minutes, or until the piths (the white parts of the lime) are translucent.
Remove the lime slices to a cooling rack. I suggest you place some tin foil underneath the rack for easy cleanup - these slices get very sticky as they dry!
Once the lime slices are mostly dried, toss them in some sugar and let them set on a sheet of wax paper.
Top each one of your cupcakes with a delicious candied lime slice and enjoy!