Preheat the oven to 350 degrees.

Line a muffin tin with 12 blue cupcake liners.

In a medium bowl combine the flour, baking powder, and salt. Set aside.

In a large bowl cream together the butter and sugar.

Add in the egg, lemon juice, lemon zest, and extract. Mix well to combine.

Add half the flour mixture to the butter mixture and mix well.

Add the milk and mix well to combine.

Add the remaining flour mixture and mix well.

Divide the batter between the muffin cups filling 3/4 of the way full.

Bake for 20-25 minutes or until a toothpick inserted into the center comes out clean.

Remove from muffin tin and cool completely on a wire rack.

To make the frosting place the butter in a large bowl and beat until smooth. Add the powdered sugar a cup at a time, beating after each addition.

Mix in the vanilla and milk and beat until smooth.

Cover the tops of the cupcakes with the buttercream frosting then roll in the mermaid sprinkles.

Stick a mermaid candy in the top of each cupcake and enjoy!