In large bowl, with mixer at low speed, beat sugar and butter until blended.
Increase speed to high; beat until light and fluffy, about 5 minutes.
At medium speed, beat in ricotta, lemon juice and zest and the egg until well combined.
Reduce speed to low. Add flour, baking powder, and salt; beat until dough forms.
Cover the bowl with plastic wrap and chill the dough in the refrigerator for 2 hours.
Preheat your oven to 350 degrees.
Flour your hands and take about a tablespoon of dough in you hands. Roll the dough into a rope about 1 inch thick and form a ring. Place each cookie about 2 inches apart onto and ungreased large cookie sheet. Bake about 10-12minutes or until cookies are very lightly golden (cookies will be soft)
Icing:
While the cookies are baking whisk together the confectioners sugar, lemon juice and butter until smooth. While the cookies are still hot from the oven dip them in the glaze. Decorate with sprinkles as desired.
Set cookies aside to allow icing to dry completely.