Preheat oven to 350°F. Line two standard 12-count muffin pans (or one 24-count muffin pan) with 14 cupcake liners and set aside.
In a large mixing bowl, whisk together the flour, baking powder, and salt. Set aside.
In the bowl of a stand mixer fitted with the paddle attachment, or in a large mixing bowl using a hand-held mixer, beat the butter and granulated sugar together until light and fluffy (about 4-5 minutes). Mix in each egg one at a time, then the vanilla extract, making sure to mix well after each addition. Add the lemon juice, lemon zest, and lemon extract and mix until well combined. The mixture may look curdled at this point, this is okay.
Mix in the dry ingredients in three additions alternating with the buttermilk making sure to mix well after each addition. Use a rubber spatula or spoon to turn the batter and make sure everything is well combined.
Toss the blueberries with the teaspoon of flour and gently fold them into the batter.
Evenly distribute the batter between all 14 cupcake liners, making sure to only fill them about 3/4 of the way full. Bake in separate batches at 350°F for 17-22 minutes or until a toothpick inserted into the center of the cupcakes comes out clean and the tops spring back when lightly touched.
Remove from the oven, then carefully remove the cupcakes from the pan and transfer to a wire rack to cool.