Preheat oven to 350°F. Oil and flour 2 standard size muffin tins. In a medium bowl, whisk together flours, starches, baking powder, salt and xanthan gum. Cream 1 cup sugar and palm shortening in a large bowl.  Once shortening and sugar mixture is light and fluffy, slowly add eggs one at a time.  After eggs are added, slowly add the flour blend mixture and liquids.Once ingredients are thoroughly mixed pour batter into muffin tins.  Bake for approximately 20 minutes.

While cakes are baking, combine ⅔ cup water and ⅔ cup sugar in a small saucepan and bring to a simmer.  Add 1 slice of orange, lemon and lime and allow to simmer for approximately 5 minutes. After removing from oven, while still in the pans, poke holes in the top of the cakes with a toothpick and drizzle approximately ½ teaspoon of syrup over each cake.  After cooling for approximately 10 minutes, remove cakes from pan.  Top with citrus slices and serve.