Bright & Zesty Lemon Cupcakes with Lemon Curd & Mascarpone Buttercream

👩‍🍳 Instructions

1. 1

   For the Lemon Curd: In a medium heatproof bowl, whisk egg yolks, ½ cup granulated sugar, ¼ cup lemon juice, 1 tbsp lemon zest, and pinch of salt. Set bowl over a saucepan of simmering water (not touching water). Whisk constantly 8-12 minutes until thickened (170°F/77°C). Remove from heat, whisk in cold butter pieces one at a time until melted. Strain through a fine-mesh sieve. Cover surface directly with plastic wrap and refrigerate 2+ hours until firm.
2. 2

   For the Lemon Cupcakes: Preheat oven to 350°F (175°C). Line a 12-cup muffin pan. In a medium bowl, whisk flour, baking powder, baking soda, and ¼ tsp salt. Set aside. In a large bowl, cream ½ cup softened butter and 1½ cups granulated sugar until light and fluffy (3-4 mins). Beat in eggs one at a time, then vanilla, ¼ cup lemon juice, and 2 tbsp lemon zest.
3. 3

   In a small bowl, whisk sour cream and buttermilk. With mixer on low, alternately add dry ingredients and sour cream mixture to wet, beginning and ending with dry. Mix until just combined. Divide batter evenly among liners (2/3 full). Bake 18-22 minutes until a skewer comes out clean. Cool in pan 5 mins, then transfer to wire rack to cool completely.
4. 4

   For the Mascarpone Lemon Buttercream: In a large bowl, beat 1 cup softened butter until creamy (2 mins). Add cold mascarpone cheese and beat until just combined. Gradually add sifted powdered sugar, 1 cup at a time, mixing on low then medium until smooth. Stir in 2 tbsp lemon juice, 1 tbsp lemon zest, and pinch of salt. Beat on medium-high for 1-2 minutes until light and fluffy. Adjust consistency with more lemon juice/milk or powdered sugar if needed.
5. 5

   Assembly: Once cupcakes are completely cool, use a small knife or corer to hollow out a cavity from the center of each. Fill generously with chilled lemon curd. Pipe or spread mascarpone lemon buttercream onto each cupcake. Garnish with extra lemon zest or a lemon slice if desired.