Blueberry-Filled Cupcakes with Lime Frosting

There’s a lovely surprise in these cupcakes: a sweet blueberry filling hides under a rich, citrusy cream cheese frosting.

MAKES: 18 cupcakes

PREP TIME: 50 minutes

COOKING TIME: about 30 minutes

INGREDIENTS:

CUPCAKES

• 1 cup cake-and-pastry flour
• 1 cup all-purpose flour
• 2 tsp baking powder
• ½ tsp fine sea salt
• ½ cup whole milk
• 2 large eggs
• 2 tsp vanilla extract
• 1 vanilla bean
• ¾ cup unsalted butter, softened
• 1 cup granulated sugar

BLUEBERRY FILLING

• ⅓ cup granulated sugar
• 1 tsp cornstarch
• 1 cup fresh or frozen blueberries
• ⅓ cup water
• 1 Tbsp freshly squeezed lime juice (1 lime)

LIME FROSTING

• 1 pkg (8 oz/250 g) brick-style cream cheese, at room temperature
• ¼ cup unsalted butter, softened
• 4 cups icing sugar, sifted
• 1 Tbsp finely grated lime zest (2 to 3 limes)
• 1 Tbsp freshly squeezed lime juice (1 lime)
• 1 tsp vanilla extract
• ½ tsp fine sea salt
• Additional fresh blueberries and lime slices for garnish (optional)

INSTRUCTIONS:

1.  Preheat the oven to 350°F. Line two muffin pans with 18 large paper liners, then set aside. Pour water into any empty wells to prevent burning.
2. For the cupcakes, whisk both flours, the baking powder and salt in a medium bowl. Set aside.
3. In a small bowl, whisk ¼ cup of milk, the eggs and vanilla extract.
4. Using a sharp knife, split the vanilla bean in half lengthwise. Scrape out the seeds into the milk mixture. Whisk well, then set aside. Discard the vanilla bean.
5. In a large bowl and using an electric mixer, beat the butter with the sugar until pale and fluffy, about 3 minutes. With the mixer running on low speed, beat in the flour mixture and the remaining ¼ cup of milk just until combined. Increase the speed to medium-high. Beat for 2 minutes, scraping down the sides of the bowl once or twice.
6. With the mixer running on low speed, beat one-third of the egg mixture into the sugar mixture. Increase the speed to medium and beat until the egg mixture is fully incorporated before adding half of the remaining egg mixture. Repeat with the remaining egg.
7. Fill the paper liners about two-thirds full with batter. Bake until the cupcakes spring back when lightly touched and a wooden skewer inserted in the centre of a cupcake comes out clean, about 20 minutes.
8. Let the cupcakes cool in the pans for 10 minutes, then remove to a wire rack and cool completely. (The undecorated cupcakes can be refrigerated in an airtight container for up to 4 days.)
9. For the blueberry filling, whisk the sugar and cornstarch in a small saucepan. Stir in the blueberries, water and lime juice. Cook over medium-low heat, stirring occasionally, until the blueberries have burst and the mixture coats the back of a spoon, 8 to 10 minutes. Let cool completely.
10. For the frosting, in a large bowl and using an electric mixer on medium speed, beat the cream cheese and butter until smooth. Beat in the icing sugar, 1 cup at a time, until the frosting is smooth and fluffy. Beat in the lime zest and juice, vanilla extract and salt until well combined.
11. To assemble the cupcakes, use a small, sharp knife to cut a cone-shaped piece, about 1 inch deep and ¾ inch wide, from the top of each cupcake. Slice off and discard the pointy underside of each cone-shaped piece. Fill the cavity in each cupcake with the blueberry filling. Replace the tops.
12. Using an offset spatula or a piping bag, swirl the frosting on top of the cupcakes. Garnish with blueberries and lime slices. (The frosted cupcakes—without the garnish—can be refrigerated in an airtight container for up to 3 days. Bring them to room temperature before serving.)