Puree the oranges in a food processor (add the date if using). Beat the eggs in a blender until fluffy, then add all the main ingredients (and any optional ones you like).

Preheat the oven to 375°F (190°C) with convection. Fill muffin cups 3/4 full with the batter and bake for 15 minutes. (If you like, add chopped fruit on top before baking.)

Once baked, let them cool for 10 minutes before removing from the muffin tin. The basic recipe is fantastic and can be adapted in many ways, even for adults.