Key Lime Cupcakes
- 1 box (18.5-ounce) yellow cake mix with pudding
- 1 package (3.9 ounce) vanilla pudding
- ½ cup of granulated sugar
- ¼ cup of vegetable oil
- ¾ cup of water
- 4 large eggs at room temperature
- 1 container (8-ounce) sour cream
- 4 egg yolks
- 1 can (14-ounce) sweetened condensed milk
- ⅔ cup key lime juice
- 2 tablespoons corn starch
- Zest of 1 lime
- 1½ cups plus 2 tablespoons of granulated sugar
- ¾ cup of water
- 2 tablespoons of light corn syrup
- 6 large egg whites, at room temperature
Since cupcakes are the "in" thing now, this is a great cupcake recipe. Don't let the lengthiness of the recipe scare you. It is time consuming, but worth the effort. After you make them once, it gets easier. This makes 2 dozen cupcakes.
Preheat oven to 350 degrees. Combine cake mix, instant pudding and sugar in a large bowl. Blend with a whisk to break up some of the lumps. Add the next 4 ingredients and mix with a hand-held mixer on low to just combine ingredients. Scrape down sides and bottom of bowl with a rubber spatula to make sure all dry ingredients are combined. Continue to mix on high for about 2 minutes. Place 24 cupcake liners in your cupcake pan and fill each liner half full. Cook at 350 degrees for 20–25 minutes or until a toothpick comes out clean. Remove from oven and cool. While cupcakes are cooling, prepare the frosting.
Constructing your cupcakes
Core out the center of each cupcake. You can use a 1-inch biscuit/pastry cutter or with a knife being careful not to core all the way to the bottom. Reserve the top of the cupcake. Fill each cupcake with a heaping tablespoon of filling and then replace reserved cake top on all 24. Frost cupcakes from a pastry bag or with a knife. Sprinkle each with graham cracker crumbs (optional) and top with lime zest sprinkles.
Whip the egg yolks and the lime zest at high speed until the yolks are a light yellow color and fluffy, about 5–6 minutes. Gradually add condensed milk and continue to whip at high speed for 4–5 minutes or until thick. On low mixer speed, slowly add lime juice. Mixture will separate, then gradually blend back together. Mix until well incorporated. Pour the mixture in a medium saucepan.
In a separate bowl, mix 2 tablespoons of corn starch and about ⅓ cup of the key lime filling mixture. Whisk well to remove clumps. Combine the key lime and starch mixture into saucepan. Bring mixture to a slow boil over medium heat and cook until it begins to thicken. Remove from heat and cool to room temperature, then refrigerate until it cools to a thick custard consistency. While the filling is cooling, prepare the cake batter.
In a small, heavy saucepan, combine 1½ cups of sugar, corn syrup and water. Clip candy thermometer to the side of the saucepan. Heat over medium heat, stirring occasionally, until sugar is dissolved. Rub a bit between your fingers to make sure there is no graininess. Raise heat and bring to a boil. Do not stir, but wash down sides of pan with a pastry brush dipped in cold water from time to time to prevent the sugar from crystallizing, until a candy thermometer registers 230 degrees about 5 minutes.
Meanwhile, in a bowl mix egg whites on medium speed until soft peaks form, about 2½ minutes. Gradually add remaining 2 tablespoons sugar. Remove the syrup from the heat when the temperature reaches 230 degrees (it will keep rising as pan is removed from heat). Pour the syrup in a steady stream down the side of the bowl containing the egg-white mixture, with the mixer on medium-low speed.
Beat frosting on medium speed until cool, 5 to 10 minutes or until the bottom of the mixer bowl is cool to the touch. The frosting should be thick and shiny. Use immediately.