In figuring out how to make an American flag roll cake, I wanted a lemon sponge cake that was well aerated and soft in texture, pliable yet had the firm structure to hold up after rolling. This delicious lemon sponge cake can be baked plain and finished off with just a dusting of powdered sugar. Or, if you’re feeling crafty and would like to dress it up for a holiday such as Independence Day, Veterans Day, Memorial Day or even Thanksgiving, you can bake a flag pattern onto the cake. Or you can customize the pattern based on your country’s flag. Any baked-on design truly makes a roll cake something that’s not only a joy to eat but a delight to behold as well.