Lemon Blueberry Cupcakes

Ingredients

• 2 cups plus 6 tablespoons all-purpose flour
• 2 teaspoons baking powder
• 1 teaspoon salt
• 3 cups fresh blueberries
• 1/2 cup sour cream
• 1/2 cup whole milk
• 2 teaspoons vanilla extract
• 3/4 teaspoon pure lemon extract
• 1 teaspoon lemon zest
• 1 cup (2 sticks) unsalted butter, room temperature
• 1 1/2 cups white sugar
• 4 large eggs
• Lemon Curd
• 1/2 cup unsalted butter
• 1/2 cup lemon juice
• zest of one large lemon ( I used 2)
• 3/4 cup granulated sugar
• 1 teaspoon cornstarch
• pinch of salt
• 6 large egg yolks
• Lemon Mascarpone Cream Frosting
• 1 pound mascarpone cheese
• 2/3 cup lemon curd
• 2 cups heavy cream
• 7 Tb sugar