Preheat oven to 325 F. Beat the egg yolks and whole eggs in the bowl of a stand mixer. Add the sugar, lemon juice and zest and beat slightly. Add the potato starch and mix to blend. In another bowl beat the egg whites until stiff but not dry. Fold the beaten egg whites into the batter. Carefully pour half of the batter into a 10″ non-stick tube pan also known as an angel food cake pan. Mix about 1 cup of the remaining batter with a tablespoon of ground cinnamon and drop by spoonfuls onto batter in pan. Cut through in a swirl pattern with a metal spatula to marbleize then pour remaining batter into pan. Bake for 50 minutes. Remove from oven, place on a cooling rack and wrap with kitchen towel to keep moisture in pan as the cake cools. When completely cool remove cake from pan and ice with frosting of your choice.