In large bowl of an electric mixer, beat 1 cup of the sugar and butter until well blended.
Add lemon peel and juice; mix to blend.
Beat in eggs, 1 at a time, until smooth.
Gradually stir in 3 cups of the flour, mixing well, cover and chill until dough is firm enough to handle easily, at least 3 hours or as long as 2 days.
For easier handling, chill the dough before you form the ring-shaped cookies.
Divide dough in half.
Cover and chill 1 portion. Divide other half into 8 equal pieces.
With floured fingers, roll each piece on a lightly floured board to make a 10-inch rope.
Overlap ends of each rope slightly to form a ring.
Place rings about 1 inch apart on a greased 14x17 inch baking sheet.
Sprinkle light with sugar.
Bake in a 300℉ (150℃). oven until golden, 35 to 40 minutes. Remove cookies from pans and let cool completely on racks.
Repeat with remaining dough..