In a food processor add the almonds and process until finely ground. About 1 minute. Set aside.
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, almond extract, ground almonds and egg until well combined.
Reduce speed to low. Add flour, baking powder, and salt; beat until dough forms.
Take about a rounded tablespoon of dough and roll into balls or drop dough by level tablespoons, about 2 inches apart, onto ungreased large cookie sheet.
If using, place the halved cherries in the center of the cookies.
Bake about 12-15 minutes or until cookies are very lightly golden (cookies will be soft).
Cool completely before Icing.
For the Icing:
In small bowl, stir powdered sugar, milk and almond extract until smooth. Drizzle the icing on cookies and decorate with nonpareils
Set cookies aside to allow icing to dry completely.