Preheat your oven to 350 degrees Fahrenheit. While your oven warms up, line a muffin tin with 12 cupcake liners. Take a moment to appreciate the anticipation of the sweet delights that are about to be made!
In a medium bowl, mix together 1 ¼ cups of all-purpose flour, ½ teaspoon of baking powder, ¼ teaspoon of baking soda, and ¼ teaspoon of salt. Make sure they are thoroughly combined and then set the bowl aside; this will be your dry mixture.
In a large mixing bowl, use an electric or stand mixer on medium speed to whisk together 2 large eggs and 1 cup of granulated sugar for about 2 minutes. You want the mixture to turn light and creamy, which sets the foundation for a fluffy cupcake.
Add ½ cup of softened unsalted butter and 1 ½ teaspoons of vanilla extract to the egg mixture. Whisk on low speed for about 1 minute, until everything is well blended. The batter should be smooth and creamy.
Slowly add in your flour mixture to the egg mixture while mixing on low speed until just incorporated. Be careful not to overmix, as this can make the cupcakes dense. You’re aiming for a thick, but smooth batter.
Next, add in ½ cup of sour cream, the zest of 1 lemon, and 2 tablespoons of lemon juice. Beat until the batter is completely smooth, and then gently fold in 1 cup of fresh blueberries. You’ll want to distribute the blueberries evenly for a berry-filled surprise in every bite!
Fill each cupcake liner about ¾ of the way full with the batter. This will allow room for the cupcakes to rise while baking. Try to be consistent with the amount you fill each liner for even baking.
Place your muffin tin in the oven and bake for 18 to 20 minutes. Check for doneness by inserting a toothpick in the center of a cupcake; it should come out clean when they are ready. The top should be lightly golden and spring back when touched.
Once baked, allow the cupcakes to cool in the tin for about 5 minutes before transferring them to a wire rack to cool completely. This is the perfect time to prepare your frosting!
In a clean mixing bowl, beat 1 cup of softened unsalted butter on medium speed for about 30 seconds until it’s smooth and creamy. This will be the base for your frosting.
Add in 2 ½ cups of powdered sugar, ¼ teaspoon of vanilla extract, 1 tablespoon of lemon juice, and 1 tablespoon of heavy whipping cream. Increase the speed to high and beat for about 3 minutes. If needed, add a little more cream for a smoother frosting consistency.
Once your cupcakes have completely cooled, frost them using a piping bag or a knife. The frosting should be creamy and smooth. Top each cupcake with yellow sprinkles and extra blueberries for that finishing touch!
