- You can make your own almond meal by running almonds through the food processor until finely ground. Start off with 1 cup of almonds and measure the ground almonds.
- Bring the two whole oranges to a boil in a large pot of water. Once boiling, turn down to simmer for about 2 hours or longer until fairly soft to touch. Remove the whole oranges from the water and let cool to room temperature.
- Cut the cooled oranges in half. Check for seeds and remove them. Put the orange halves - peel included - into the food processor and process until the skin is in tiny pieces, like zest. (If you don't have a food processor, you can put them in a stand mixer instead.)
- Beat the eggs and sugar in a large mixing bowl. Add the almond meal, and baking powder; mix well.
- Lastly add the orange mixture and stir until blended.
- Pour the batter into a greased 8-inch springform pan and bake in preheated oven at 375 degrees. You will probably need to put the pan on a baking sheet, as some of the batter may leak out.
- Check the oven after about 40 minutes to make sure the top of the cake isn't burning. If it is, cover lightly with aluminum foil and continue to cook for about 10 more minutes or until a knife inserted in the middle comes out clean.
- Cool the cake thoroughly before trying to remove it from the springform pan. It's a very moist cake, so don't be upset if it tears. It will still be tasty AND gluten-free!
- Serve thin slices, as it is very rich - topped with whipped cream or dust with confectioner's sugar and a small dab of orange marmalade or an orange twist.