• Preheat oven to 350 degrees Fahrenheit. Line a muffin tin with 12 cupcake liners. Set aside.
• In a medium bowl, mix 1 ¼ cups all-purpose flour, ½ teaspoon baking powder, ¼ teaspoon baking soda, and ¼ teaspoon salt. Set aside.
• In a large bowl, using an electric or stand mixer on medium speed, whisk 2 large eggs and 1 cup granulated sugar for about 2 minutes, or until light and creamy.
• Add the ½ cup softened unsalted butter and 1 ½ teaspoons vanilla extract and whisk on low speed for about 1 minute, or until well blended. Add the flour mixture to the egg mixture on low speed until incorporated, do not overmix! Add the ½ cup sour cream, zest of 1 lemon, and 2 tablespoons lemon juice and beat until smooth. Fold in 1 cup blueberries.
• Fill each cupcake liner about 3/4 the way full with cupcake batter. Bake for 18 to 20 minutes or until a toothpick inserted in the center comes out clean. Allow cupcakes to cool before frosting.

Lemon Buttercream Frosting:

• Mix 1 cup softened unsalted butter on medium speed with an electric or stand mixer for about 30 seconds until smooth and creamy.
• Add the 2 ½ cups powdered sugar, ¼ teaspoon vanilla extract, 1 tablespoon lemon juice, and 1 tablespoon heavy whipping cream. Increase to high speed and beat for 3 minutes. Add more cream if needed for a smoother consistency.
• Frost the cupcakes using a piping bag or knife. Top with yellow sprinkles and extra blueberries,.