The pie we loved as a youngster served as the inspiration for these Key Lime Pie Cupcakes. They have a key lime pie filling inside that tastes much like the pie you'd buy from a bakery, and marshmallow frosting that has been toasted with a kitchen torch tops them off. You'll be left wondering why you've never eaten these cupcakes before!
Key limes are little limes with a stronger, more noticeable acidic flavor. If key limes are unavailable, ordinary limes will do.
Yield: 14 cupcakes
Key Lime Cupcakes
- 2 eggs, at room temperature
- 1½ cups (191 g) all-purpose flour
- ¾ cup (150 g) granulated sugar
- ¼ teaspoon baking soda
- 1 teaspoon baking powder
- ¼ teaspoon fine sea salt
- ½ cup (120 ml) vegetable oil
- ½ cup (120 ml) milk, at room temperature
- 2 tablespoons (10 g) key lime zest
- ⅓ cup (78 ml) Key lime juice
- 1 teaspoon vanilla extract
Key Lime Pie Filling
- ¼ cup (60 ml) condensed milk
- ½ cup (113 g) cream cheese, at room temperature
- 1 tablespoon (5 g) key lime zest
- 1½ tablespoons (22 ml) of key lime juice
Marshmallow Frosting
- 1 cup (200 g) granulated sugar
- 4 large egg whites
- ¼ teaspoon of fine sea salt
- 1 teaspoon vanilla extract
- ¼ tablespoon cream of tartar
- 1 oz (28 g) Graham cracker crumbs, for garnish (optional)
Set your oven to 350°F (177°C) and prepare 14 cupcake tins by lining them with cupcake liners before you begin making the Key Lime Cupcakes.
Sift the flour, baking soda, baking powder, and salt in a large mixing bowl; set aside.
Whisk the eggs and oil in a separate, large mixing bowl. Whisk in the granulated sugar until well mixed. Whisk in the vanilla extract, milk, lime juice, and zest. Then, combine and smooth out the mixture by adding the sifted dry ingredients.
Fill the cupcake liners about two-thirds full with batter. Bake for approximately 18 minutes. Begin checking the cupcakes after 15 minutes and continue baking and monitoring as needed. To check if the cupcakes are done, lightly push your finger on the top of the cupcakes; if they spring back, they are finished baking. Before adding frosting and filling, let the cupcakes cool fully.
Using an electric mixer, whip the cream cheese for 3 minutes at medium-high speed, or until it is creamy and fluffy, to make the key lime pie filling. Continue beating for another minute after adding the condensed milk. Finally, mix in the lime juice, zest, and cream until thoroughly blended and smooth.
Egg whites, sugar, cream of tartar, salt, and granulated sugar should be mixed in a heat-resistant mixing bowl to make the marshmallow frosting. To create a double boiler, place the bowl over a saucepan of barely simmering water. We don't want the egg whites to cook, so make sure the water isn't boiling and the bottom of the bowl isn't touching the water surface.
On a candy thermometer, the mixture should read 140°F (60°C) after a few minutes of whisking. Remove the bowl from the double boiler after the syrup reaches this temperature and the sugar is fully melted. On high speed, whip the syrup for almost 5 minutes using an electric mixer that has a whisk attachment.
Each cupcake's center should be removed using a spoon before assembling the dessert. The key lime pie filling should be spooned or piped into the center of each cupcake. Fill a piping bag with marshmallow frosting and a tip of your choosing. Top each cupcake with a dollop of icing. To add a final touch, toast the frosting using a kitchen torch. If you want to decorate the cupcakes, add some crushed graham crumbs.
You can store the cupcakes for up to 4 days, covered, in the refrigerator.