1. Beat eggs and sweetener in a large bowl.
2. Heat margarine in a saucepan.
3. Add orange zest and remove from heat.
4. Combine diced orange, rice, margarine mixture, and vanilla extract.
5. Carefully fold in the egg mixture.
6. Mix quickly and pour into a non-stick loaf pan.
7. Bake for 30 to 40 minutes at 375°F.
8. Can be served warm or chilled. Sprinkle with cinnamon (optional).