Lemon Cupcakes with Lemon-Blueberry Frosting

Introduction

You get a double hit of bright, sunny lemon in these tender, fluffy cupcakes, perfectly balanced by the subtle tang of a creamy blueberry-infused frosting. They’re an ideal treat for spring gatherings, afternoon tea, or whenever you need a little burst of cheerful flavor. The contrast between the soft cupcake and the vibrant, fruity buttercream is simply irresistible.

Prep & Cook Time

• Prep Time: 45 minutes
• Cook Time: 20 minutes
• Total Time: 1 hour 5 minutes (plus cooling)
• Servings: 24 cupcakes

Ingredients

• 2 1/4 cups cake flour (I used Swan’s Down brand)
• 2 teaspoons baking powder
• 1/2 teaspoon fine grain sea salt
• 1 1/4 cups buttermilk (room temperature)
• 1 teaspoon pure vanilla extract
• 1/2 teaspoon pure lemon extract
• 1 1/2 cups sugar
• lemon zest from two lemons (finely grated)
• 12 tablespoons unsalted butter (room temperature)
• 4 large egg whites (room temperature)
• Prepared lemon curd
• 2 cups unsalted butter (softened)
• 2 pounds confectioners’ sugar (sifted)
• pinch of fine grain sea salt
• 2 teaspoons pure vanilla extract
• zest of one lemon (finely grated)
• ½ cup fresh blueberries (pureed with 1 tablespoon fresh lemon juice)
• 1-3 tablespoons very cold milk

Instructions

For the Lemon Cupcakes:

1. Preheat your oven to 350°F (175°C). Line two standard muffin tins with 24 paper liners.
2. In a medium bowl, whisk together the cake flour, baking powder, and 1/2 teaspoon fine grain sea salt. Set aside.
3. In a liquid measuring cup or small bowl, combine the buttermilk, vanilla extract, and lemon extract. Set aside.
4. In the bowl of a stand mixer fitted with the paddle attachment, combine the sugar and lemon zest from two lemons. Rub them together with your fingers for a minute until fragrant.
5. Add the 12 tablespoons of room-temperature butter to the sugar-zest mixture. Beat on medium-high speed for 3-4 minutes until light and fluffy.
6. In a clean, grease-free bowl, beat the 4 large egg whites with a hand mixer until stiff peaks form. Gently fold the egg whites into the batter in three additions until no white streaks remain.
7. Divide the batter evenly among the 24 prepared liners, filling each about 2/3 full.
8. Bake for 18-20 minutes, or until a toothpick inserted into the center of a cupcake comes out clean. Allow the cupcakes to cool in the pans for 5 minutes before transferring them to a wire rack to cool completely.

For the Lemon-Blueberry Frosting:

1. While the cupcakes cool, prepare the blueberry puree. In a small blender or food processor, puree the 1/2 cup fresh blueberries with 1 tablespoon fresh lemon juice until smooth. Set aside.
2. In the bowl of a stand mixer fitted with the paddle attachment, beat the 2 cups of softened butter on medium speed for 2-3 minutes until creamy and pale.
3. With the mixer on low, gradually add the sifted confectioners’ sugar, a pinch of fine grain sea salt, and the 2 teaspoons of vanilla extract. Mix until combined.
4. Increase the speed to medium-high and beat for 3-4 minutes, until the frosting is very light and fluffy.
5. Add the zest of one lemon and the blueberry puree. Beat on medium speed until fully incorporated.
6. If the frosting is too thick, add the very cold milk, one tablespoon at a time, until your desired piping consistency is reached.

To Assemble:

1. Once cupcakes are completely cool, use a small paring knife or a cupcake corer to remove a small plug of cake from the center of each.
2. Fill each cavity with a small spoonful of prepared lemon curd.
3. Fit a piping bag with your favorite tip and fill it with the Lemon-Blueberry Frosting. Frost each cupcake generously.

Variations

• Frosting Swirl: For a marbled effect, add the blueberry puree to only half of the finished frosting. Spoon both the plain lemon and the blueberry lemon frosting side-by-side into your piping bag.
• Lemon Glaze: For a simpler, less sweet topping, skip the buttercream and drizzle the filled cupcakes with a simple glaze made from the lemon curd thinned with a little milk.
• Mini Cupcakes: Bake as mini cupcakes for about 10-12 minutes. This recipe will yield approximately 48 mini treats perfect for parties.
• Deconstructed Dessert: Crumble the cupcake into a glass, layer with lemon curd and a dollop of the frosting, and top with fresh blueberries for a fun parfait.

Tips for Success

• Room Temperature is Key: Having your buttermilk, butter, and egg whites at room temperature ensures a smooth, emulsified batter that rises evenly for a tender crumb.
• Don’t Overmix the Batter: Once you add the flour, mix only until the ingredients are combined. Overmixing develops gluten, leading to dense, tough cupcakes.
• Sift Your Sugar: Sifting the confectioners’ sugar for the frosting prevents lumps and creates an exceptionally smooth and silky buttercream.
• Cold Milk for Frosting: Use very cold milk to thin the frosting if needed. If the butter starts to get too soft from beating, the cold milk helps firm it back up for perfect piping consistency.

Storage & Reheating

Store frosted cupcakes in an airtight container in the refrigerator for up to 3 days. Let them sit at room temperature for 30 minutes before serving for the best texture and flavor. Unfrosted cupcakes can be frozen for up to 2 months; thaw at room temperature before filling and frosting.

FAQ

Can I use all-purpose flour instead of cake flour?

You can, but the texture will be slightly denser. For a closer result, replace 2 tablespoons per cup of all-purpose flour with cornstarch (so for this recipe, use 2 cups + 2 tbsp all-purpose flour and 6 tbsp cornstarch, whisked together).

My blueberry puree has seeds and skin. Should I strain it?

It’s not necessary, but for an ultra-smooth frosting with a consistent purple color, you can press the puree through a fine-mesh sieve to remove the skins and seeds.

What can I use instead of lemon extract?

You can omit it and increase the pure vanilla extract to 1 1/2 teaspoons total. The flavor will be less intensely “lemon”, but the zest and curd will still provide plenty of citrus notes.

Why did my frosting turn out gray or muddy purple?

This is natural! Blueberries can react with the acidic lemon juice and the yellow butter, sometimes creating a grayish or muted purple hue. It will still taste delicious. Using more blueberries can deepen the purple color.

Can I make the frosting ahead of time?

Yes, you can make the frosting up to 2 days ahead. Store it covered in the refrigerator, then let it come to room temperature and re-whip it with your mixer for a few minutes before using to restore its fluffy texture.

My cupcakes sunk in the middle. What happened?

This is usually caused by overmixing the batter after adding the flour, or by underbaking. Be sure to test for doneness with a toothpick—it should come out clean with no wet batter clinging to it.