Preparation

1. Adjust oven rack to the center position.  Preheat oven to 325°F.
2. Butter and flour a 6-cup ring mold (7-½ x 3 - inch Bundt) or loaf pan (8-½ x 4-½ x 2½ - inch), or two 3-¾ cup loaf pans (7-3/8 x 3-5/8 x 2¼ - inch).
3. Remove peel (yellow part only) from lemons using a vegetable peeler; cut peel into 2 - inch pieces.
4. With the metal blade in place, combing the lemon peel and sugar in bowl of food processor. Process until peel is finely chopped, about 60 seconds. Add butter and process until smooth, about 30 seconds. Add eggs and process until smooth, about 30 seconds. Scrape down sides of bowl with spatula as needed.
5. Stir flour and baking powder together; add to work bowl. Pulse on and off only until flour just disappears. Do not over process.
6. Transfer batter to prepared pan or pans. Bake in preheated oven until toothpick inserted in center comes out clean, about 50 to 55 minutes for ring mold and small loaves. Allow 10 minutes longer for the large loaf. Let cool slightly in pan. Mix together confectioners' sugar and lemon juice until blended. Remove cake from pan and place on wire rack over waxed paper. Spoon some of the glaze over the cake. Repeat as cake cools until all the glaze is used. When cool wrap in plastic wrap or foil and refrigerate.