Ingredients
Blueberry Sauce:
- 1/2 pint blueberries
- 1/2 cup white granulated sugar
- 1 tsp lemon juice
Cupcakes:
- 4 egg whites (room temperature)
- 1 cup white granulated sugar
- 1 tsp vanilla extract
- 1/2 cup vegetable oil
- 2 cups all purpose flour
- 1 tsp baking powder
- 1/2 tsp baking soda
- 1/8 tsp salt
- 1 cup low fat buttermilk
- Zest of 3 key limes
Frosting:
- 8 oz cream cheese (room temperature)
- 1/2 cup unsalted butter (room temperature)
- 2 Tbsp blueberry sauce
- 1 1/2 cups powdered sugar
Instructions
- Make Blueberry Sauce: Add blueberries to a small sauce pot and heat over medium heat. Stir in lemon juice and sugar well. Cover the pot leaving a small crack for steam to escape and cook for about 15 minutes, stirring often to prevent burning and over-running. Strain off about 3 tablespoons of juice for drizzling on cupcakes later and puree the remaining mixture in a blender until smooth.
- Prepare Cupcake Batter: Preheat the oven to 350°F (175°C) and line a muffin pan with cupcake liners. In a medium bowl, sift together flour, baking powder, baking soda, and salt. Set aside. Make sure all other ingredients are ready for use.
- Whip Egg Whites and Sugar: Using an electric mixer fitted with a paddle attachment, beat the egg whites for a few seconds, then gradually pour in sugar while continuing to beat. Beat for 3-4 minutes until the mixture becomes white and fluffy.
- Add Oil and Vanilla: Slowly pour the vegetable oil into the egg mixture while continuing to mix on medium-high speed. Add the vanilla extract and reduce the speed to low.
- Combine Dry and Wet Ingredients: Alternately add the sifted flour mixture and buttermilk in two parts to the batter, mixing just until combined each time. Be careful not to overmix to keep the cupcakes light and fluffy.
- Add Key Lime Zest: Fold in the zest of 3 key limes, scraping down the sides and bottom of the bowl to ensure even distribution.
- Fill and Bake: Divide the batter evenly among the cupcake liners, filling each about two-thirds full. Bake in the preheated oven for 18-20 minutes, or until a toothpick inserted into the center comes out clean.
- Cool Cupcakes: Remove cupcakes from the oven and allow them to cool completely on a wire rack before frosting.
- Prepare Frosting: In a large bowl, beat cream cheese and unsalted butter together on medium-high speed until smooth and creamy, about 1-2 minutes.
- Add Powdered Sugar and Blueberry Sauce: Reduce mixer speed to low and incorporate powdered sugar and 2 tablespoons of blueberry sauce into the frosting mixture.
- Whip Frosting: Increase speed back to medium-high and beat for 3-4 minutes until the frosting is light, smooth, and fluffy.
- Frost and Serve: Spread or pipe the blueberry cream cheese frosting onto the cooled cupcakes. Drizzle each cupcake with the reserved blueberry sauce for an extra burst of flavor and visual appeal.
Notes
- Ensure egg whites are at room temperature before whipping to achieve maximum volume.
- When folding in dry ingredients, mix just until combined to maintain cupcake tenderness.
- Monitor blueberry sauce closely while cooking to avoid overcooking and burning.
- Use fresh key limes for authentic tart flavor; regular limes can be used if key limes are unavailable but flavor will be less distinct.
- For best results, cool cupcakes completely before frosting to prevent melting of the frosting.
- Prep Time: 40 minutes
- Cook Time: 20 minutes
- Category: Dessert
- Method: Baking
- Cuisine: American