Preheat the oven to 350 degrees.

In a larger bowl cream the butter, sugar, and brown sugar. Add in the egg, lemon juice, lemon zest, and lemon extract and mix well.

In a medium bowl combine the flour, baking soda, and salt.

Add the flour mixture to the butter mixture and mix until just combined.

Divide the dough into 8 portions and place the on the baking sheet.

Bake for 10 minutes or until they have set.

Let cool on the baking sheet for 5 minutes then remove to a wire rack to cool completely.

In a small saucepan melt the butter, powdered sugar, lemon zest, and lemon juice over medium heat stirring constantly until the sugar dissolves.

Remove from heat and brush over cooled cookies.