Use an electric mixer on medium speed to blend sugar, butter, vanilla, salt and ricotta cheese. Gradually stir in flour; mix in baking soda. Drop by teaspoonfuls onto ungreased baking sheets. Bake at 350 degrees for 10 to 13 minutes. Cool on wire racks. To prepare Sweet Vanilla Icing: mix all icing ingredients with an electric mixer on low speed. Spread Sweet Vanilla Icing over cookies.