01 -
Preheat oven to 350 degrees Fahrenheit. Line a 12-serving cupcake pan with paper liners. Set aside.
02 -
Add flour, baking powder, and lemon zest to a small mixing bowl and whisk to combine. Set aside.
03 -
In a large mixing bowl, cream the butter and sugar with an electric mixer. Add the eggs and mix until very well combined.
04 -
Add the dry ingredients and mix until smooth. Scrape down the sides of the bowl with a rubber spatula, then add the milk, vanilla, and lemon juice. Beat the batter until it's very smooth and fluffy - about 2 minutes.
05 -
Spoon the batter evenly into the cupcake liners in a muffin pan until each one is approximately ¾ full.
06 -
Bake for 16 minutes, or until a toothpick inserted into one of the cupcakes comes out clean. Carefully remove the cupcakes from the pan and place them on a wire cooling rack to cool completely.
07 -
Add the butter and powdered sugar to a large mixing bowl and mix with an electric mixer until just combined. The mixture will look very dry.
08 -
Place the blueberries in a food processor and puree.
09 -
Pour the pureed blueberries into the mixing bowl and beat until creamy, scraping down the sides of the mixing bowl with a rubber spatula several times to ensure all ingredients are fully incorporated. If the buttercream appears too dry, add a small splash of milk and continue to beat well.
10 -
Add the buttercream to a large piping bag fitted with a large star tip and pipe a generous swirl of buttercream onto each cupcake. Garnish with extra blueberries.