Preheat the oven to 350 degrees. Line a cookie sheet with parchment paper.

In a medium bowl mix together the flour, baking powder, and salt.

In a large bowl cream together the butter and sugar. Add in the eggs and mix well.

Add the lemon zest, lemon juice, and lemon extract and mix well.

Add the dry ingredients to the wet ingredients and stir until combined.

Divide the dough in half and form each half into a 3/4 inch thick log (it should be 10-12 inches long and 3 inches wide).

Bake for 25 minutes.

Remove from oven and cool for 10 minutes.

Use the serrated knife and cut 1/4 inch slices on a diagonal.

Set the slices on their side on the baking sheet and bake for 8 minutes. Flip the biscotti over and cook for 6-8 additional minutes.

Remove from oven and cool completely.

Once cool combine the powdered sugar and lemon juice and mix well. Drizzle over top of the biscotti and allow to sit 15 minutes for the glaze to dry.