(1) It’s very important that you find organic, untreated, oranges, because the whole fruit is used, including the skin.
Carefully wash the orange in hot water, cut it into segments, eliminate any seeds and blend it finely together with its skin. Put the extra virgin olive oil, milk and sugar in a bowl and beat with a whisk (or an electric hand mixer) for a few minutes. Add one egg at a time, stirring constantly, until you obtain a frothy, liquid mixture. In another bowl, mix the three types of flour with the baking soda, and then combine them with the mixture a little at a time. Finally add the blended orange and stir again. Pour the mixture into a cake tin, well-greased with butter and dusted with almond flour. Bake in a preheated oven, at 180 °C, for roughly 45 minutes (it’s best to avoid using a fan oven, because the cake might rise less). If, around half-way through the cooking time, the surface of the cake begins to brown too much, cover with baking foil. Before removing from the oven do the “toothpick test” to see if it’s cooked. Leave the cake to cool down before removing it from the tin. When you serve the “Pan d’Arancia”, dust it with icing sugar or spread orange marmalade on top. If the marmalade is too thick, dilute it with 2-3 spoonfuls of hot water. You can also slice the cake in two horizontally, spread the marmalade on the bottom half and then put the other half back on top.