When I want to want to decorate a Lemon Poppy Seed Cake, or a Lemon Flavored Cake I use thinly sliced lemons that I have preserved in a Simple Syrup.
1. I pick pretty and clean lemons at the produce section of my supermarket. I create create a simple syrup to cover as many lemons as I will be using. I want the syrup to cover at least ¼ inch above the amount of fruit. First I wash the skin of the fruit. Give it a good scrubbing. I cut the lemon in half on the equator and pick out as many seeds as I can find. I use a toothpick as I don't want to damage the pulp of the fruit. Using my mandolin, I set it on the thinnest setting. I slice the lemon starting in the middle while trying to catch as much of the juice as possible. As the slices get small, it is now a judgement thing. If there is more skin and pith, than pulp, toss the rest.
2. Place the slices gently in the simple syrup trying to keep the slices whole and not damaging the pulp. Add any collected juices. Bring to a boil, reduce heat and simmer until the simple syrup is reduced by half. Allow to cool. Fill a jar with boiling water, allow to stand for five minutes and then empty. Sterilize the cover in a small pan with boiling water. Then place the cooked fruit gently in the impeccably clean jar. (as Julia would say). A wide mouth jar would be perfect for this step. Cover the fruit with the flavored reduced simple syrup. The skin of the lemon will be sweet and completely edible, ready for use to decorate with.
3. For the oranges, I try to find clean Florida oranges. Navel oranges have a thick pith and are not as attractive for decorating. Follow steps one and two. Florida oranges have seeds like lemons. You will find that there is a lot more juice in Florida oranges. Try to collect as much of the juices as possible.
4. To use for decorating, take slices and place neatly on top and along the sides and tops of Poppy Seed cake, Lemon Cake and any other dessert you wish to decorate with. You will find that the slices will stay on the sides on their own. The sugar mixture acts as a glue. The same goes for the orange slices. I use the slices on cupcakes to identify the flavor of the cupcake. You can also use a small amount of the syrup for flavoring. Allow te slices to drain first before placing on the cake.
5. The slices can be kept in the refrigerator for a long time as the sugar acts as a preservative.