Add white cupcake liners to cupcake baking pans. Preheat oven as directed on boxed cake mix.
Zest the lemons, and set aside.
Prepare the white boxed cake mix as directed on the box. After the cake mix ingredients are combined, add in the lemon zest. Cut the lemons in half, and add the juice of 2 lemons. Beat together until combined.
Divide cake batter evenly into lined cupcake baking pans.
Rinse 1 1/2 cups fresh blueberries and pat dry with paper towel. Drop 3-4 blueberries into the batter of each cupcake. Gently press into the batter slightly.
Bake according to boxed mix instructions for cupcakes. Cool completely before frosting, and store in refrigerator.
In a large bowl or stand mixer, beat the cream cheese, sugar, vanilla and lemon extracts until smooth. Slowly pour in the heavy whipping cream and beat on medium-high until stiff peaks form. This will take a few minutes.
Add frosting into piping bag or plastic zip bag, or just use knife and frost cooled cupcakes as desired.
Top with 3 blueberries and a sprinkle of lemon zest. Store in refrigerator.
Make sure to use white cupcake liners so that you can see the beautiful blue and purple colors of the berries.
Use your best judgement on the number of lemons for the batter. I had 2 pretty large lemons that were super juicy and that worked great, but some lemons are small and not very juicy. If you're OK with tasting raw batter, test it for how strong the lemon flavor is. Most of the flavor comes from the zest. Adjust according to taste.
The whipped frosting is my new favorite go-to. You can change the flavor and use for other desserts just by swapping extracts. Omit the lemon for just vanilla, or add almond extract for a different recipe!
These are best once they have chilled in the fridge. The blueberries tend to burst and moisten the bottom of the cupcake, but chilling them helps bring everything back together. If you are not planning to serve/eat all of the cupcakes, refrain from adding fresh zest to all of them. The zest will dry up and wilt the longer it sits.