Lime in the Coconut: Key Lime Pie Cupcakes with Coconut Meringue

This past weekend was one of the first nice weekends, and it was also my friend Sally’s birthday, which we celebrated in the Catskills. What better way to celebrate a birthday, and the weather, than with Key Lime Pie cupcakes! These graham cakes filled with a key lime custard and then topped with a coconut meringue were light and tart and generally delicious. They are also an ideal vehicle for colorful cocktail umbrellas, if you are feeling festive. They’re a little bit labor intensive, but they are definitely worth it.

For the graham cake, I used Vanilla Garlic’s recipe, modifying it just slightly with the use of soy milk and some good quality vanilla extract. The cake was everything he promised it would be– light and fluffy but distinctly tasting of graham crackers. The batter was also amazing.

For the filling, I used my own key lime custard recipe. The cupcakes are actually twice-baked, because they go back in the oven for a few minutes to cook the filling. (I’ll eat raw eggs in batter, but I don’t feel comfortable serving a filling with raw eggs to others, so I decided that a double bake was my best option. The citric acid in the lime juice does also work to “cook” the eggs though.) My cakes were still moist even after the second time in the oven, but when baking the first time, keep in mind that moister is better, as they’ll be baked again.

Cream of tartar, traditionally used in meringues, is a strangely illusive ingredient in my neighborhood, so I use white vinegar to get those fluffy egg white peaks.


Graham Cupcakes

key-lime pie cupcakesINGREDIENTS

  • 1/2 cup of butter, room temperature
  • 1 cup of sugar
  • 3 eggs, room temperature
  • 1 cup of milk (I used soy)
  • 2 teaspoons vanilla extract
  • 1 cup of flour (I used cake flour, whisked, but all-purpose should work too)
  • 1 1/2 cups of graham cracker crumbs (about a sleeve of graham crackers, finely crushed, ideally in a food processor, but a rolling pin over a plastic bag also works)
  • 1 teaspoon of baking soda
  • 1 teaspoon of baking powder
  • 1/8 teaspoon of salt

Preheat the oven to 350. Beat the butter for about 30 seconds or until well creamed. Add the sugar and mix for 3 minutes. If using a stand mixer, use the paddle attachment for this. Add the eggs, one at a time, being sure to beat for 30 seconds for each egg.

Sift or whisk together the flour, graham cracker crumbs, baking soda and powder, and salt. Slowly add to the butter mixture, alternating with milk. Continue to mix until just combined.

Scoop into cupcake liners and bake for 15-18 minutes or until a cake tester/ toothpick comes out clean.

Cut a piece of cake out of each cupcake and fill the cavity with the key lime curd mixture. (I used a grapefruit spoon to do this.)

Key Lime Filling

This also works great as a pie filling, or just as a custard baked in ramekins.


  • 3 large egg yolks (save the whites for the meringue!)
  • 1 14 oz can of sweetened condensed milk
  • 1/2 cup fresh key lime juice (don’t use bottled for this– if you can’t find key limes, it’s better to substitute other fresh limes)
  • Zest of 3 limes (reserve additional zest for garnish)
Whisk together the yolks and condensed milk until well combined. Add the lime juice and zest and whisk again. Spoon into the cavities of the cupcakes, top with coconut meringue (below) and return to the oven to bake for 5 minutes, or until filling is firm and meringue is just slightly browned. (If you are using this as a pie filling, it will take longer to bake– about 10-15 minutes. But, because there is just a tablespoon or so in each cake, it cooks much faster.)
Coconut Meringue
It’s important to make this in a clean bowl with no grease or fat residue. Just a tiny bit of yolk or grease can keep your eggs from getting fluffy. 
  • 3 egg whites
  • 1/2 teaspoon white vinegar
  • 1/2 cup white sugar
  • 1 teaspoon coconut extract or coconut rum
  • Unsweetened coconut flakes for garnish
Whisk together the egg whites and vinegar until foamy. (A stand mixer is ideal for this.) Add sugar, and continue whisking at medium speed until stiff peaks form. Fold in the coconut extract or rum. Spoon on top of each cake. Sprinkle cocunut flakes, and any reserved lime zest on top. Bake at 350 degrees for about 5 minutes. Let cook, and enjoy!