Preheat oven to 325 degrees. Prepare standard cupcake pan with liners.
In a separate bowl, mix flour (or flour + baking powder) and salt. Set aside.
In the bowl of your stand mixer, cream together butter and sugar until fluffy. I prefer the paddle attachment for this recipe.
Add eggs one at a time until combined. Once mixed, add zest, lemon juice, and vanilla extract. Mix until incorporated. Use spatula to scrape sides of the bowl until batter is well combined.
With your mixer on slow (to avoid a flour cloud), add the flour mixture one quarter at a time.
Slowly add a cup of milk. Mix until combined.
Gently fold in blueberries using a spatula.
Add batter to cupcake pan until tins are 3/4 full. Bake for 20-25 minutes.