Peel the orange and take out the pips. Grate the carrot.
Put the egg, milk, orange and spices in a blender. Pulse for a few seconds until you get a purée. Add the oat, flour, baking powder, syrup and carrot, then pulse again. Add more milk if needed - you should get a thick, but pourable batter. Stir in the raisins, if used.
Heat the waffle maker. Once it’s hot, spoon in some batter and seal. Following the machine instructions, cook the waffles for about 3-5 minutes - they should be golden and crispy on the outside, soft inside. You should be able to get 3 or 4 waffles from the mixture (depending on the size of your machine).
Serve warm or at room temperature.