Ingredients
For the cupcakes
2 cups cake flour
1 cup graham cracker crumbs
1 tbsp. baking powder
1/2 teaspoon salt
1 cup (2 sticks) unsalted butter, softened to room temperature
2 cups sugar
Zest of 1 lime (or 2-3 key limes)
4 large eggs, at room temperature
1 3/4 cups buttermilk
2 teaspoon vanilla extract
For lime curd filling:
3 large eggs
3/4 cups sugar
1/4 cup freshly squeezed lime juice
4 tablespoons unsalted butter, softened to room temperature, cut into pieces
For topping
1 1/4 cups heavy cream
2 tablespoons confectioners sugar
Dash vanilla extract
Directions
First make your lime curd. In a medium saucepan, combine the eggs and sugar. Whisk together until well blended. Whisk in the lime juice. Place the pan over medium-low heat. Cook, stirring or whisking constantly, until the mixture is warmed through. Be careful not to heat the mixture too quickly to avoid curdling the eggs. Whisk in the butter a little bit at a time, stirring in each addition until completely incorporated before adding more. Continue to cook, scraping the bottom of the pan, until the mixture thickens and a spoon or spatula leaves a path when drawn through it. Immediately remove the pan from the heat and pass the mixture through a fine mesh strainer. Transfer to an airtight container and refrigerate. (You can make this up to a week ahead of time.)
Preheat the oven to 350F. Line two cupcake pans with paper liners.
To make the cupcakes, combine the cake flour, graham crackers baking powder and salt in a medium bowl. Whisk together and set aside. Add the butter to the workbowl of your stand mixer fitted with the paddle attachment. Beat on medium-high speed for 3 minutes, until light and creamy in color. Scrape down the sides of the bowl and beat for one more minute. Add the sugar to the butter mixture, 1/4 cup at a time, beating 1 minute after each addition. Mix in the eggs one at a time until incorporated. Combine the buttermilk and the vanilla and coconut extracts in a liquid measuring cup. With the mixer on low speed, add the dry ingredients alternately with the wet ingredients, beginning and ending with the dry ingredients and mixing just until incorporated. Scrape down the sides of the bowl and mix for 15 seconds longer.
Divide the batter between the prepared paper liners, filling each about 2/3 of the way full. Bake 18-22 minutes, or until a toothpick inserted in the center comes out clean. Allow to cool in the pans 5-10 minutes, then transfer to a cooling rack to cool completely.
To assemble the cupcakes, use the cone method to make a well in the center of each cupcake. Discard the cones. Fill each well with about 1 1/2 tablespoons of the lime curd. To make the whipped cream, combine the heavy cream and confectioners’ sugar in the bowl of an electric mixer fitted with the whisk attachment. Whip on medium-high speed until stiff peaks form. Blend in the vanilla. Transfer the whipped
cream to a pastry bag fitted with a decorative tip. Pipe a rim of whipped cream around the top of each cupcake. Garnish with key lime slices if desired.