IN a medium bowl combine the flour, baking powder, and salt. Put aside.
In a large bowl, combine the butter and the sugar.
Using an electric mixer beat the butter and sugar until light and fluffy (About 3 minutes)
Add the egg, 1 at a time, beating until incorporated.
Add the ricotta cheese, lemon juice and lemon zest.
Stir in the dry ingredient (the flour, baking powder, salt mix), Make sure all ingredients are mixed well.
Line a baking sheet with parchment paper.
Spoon the dough (about two tbsp for each cookie) on to the baking sheet.
Bake for 15 minutes or until the edges are golden at the edges.
Remove from the oven and let the cookies rest on the the baking sheet for 20 minutes.
Combine the powder sugar, lemon juice, and lemon zest n a small bowl and stir until smooth.
Spoon about a half a tsp. onto each cookie and spread it over the whole cookie.
Let the glaze harden for about 2 hours then enjoy!