Preheat the oven to 375 degrees. In a mixing bowl, cream the butter and sugar until it's light in color and creamy. Add one egg at a time. Then add in the vanilla and lemon juice.

In a medium bowl, combine the flour, salt, and baking powder, then set aside. Crush 1/4 cup of the blueberries with a fork and set aside (optional).

With the mixer on low, add in the crushed blueberries, and then slowly add the flour mixture in 3 parts, alternating with the milk. Fold in the remaining blueberries by hand.

You'll need two standard muffin pans, filling 15 with liners. Fill each liner up to the top with the batter. Bake for 20-25 min. or until light golden brown. Remove from the oven and let cool. Store in a covered container. Optionally, a lemon glaze would work nicely as a topping if you want a bit more sweet.