Well in advance, slice 2 of the large seedless oranges into 12 fairly thick slices.
Simmer in a covered pan with 500ml of water and 100g of muscovado sugar for around 3 hours on an extremely low heat.
Add water as needed if liquid is going down too much.
When thoroughly candied, set aside to cool, drain and firm up,
Grease sides and line the bottom of a 9inch cake tin,
arrange the candied slices in the 9inch (25cm) cake tin. I suggest 8 larger slices on outside, 4 smaller ones in the centre. You can squish them to fit.
Mix the maple syrup with the 60ml of orange juice from the oranges, and set aside ready for when the cake is cooked.
Preheat the oven to 170°C Fan/ 180°C ordinary. Non fan is best, just above the middle of the oven.
Place the cornmeal, ground almonds, 2 different flours, sugar, baking powder, bicarbonate of soda and salt in a large bowl and whisk/mix well to combine.
In a jug add the lemon zest, orange zest, marmalade, oil, lemon juice, oat milk, yogurt and orange extract.
Add the wet ingredients to the dry ingredients.
whisk well, but quickly until no dry lumps remain.
Pour the batter quickly into the prepared cake tin and shake if necessary, to level it.
Bake for about 50 minutes at 180°C (non fan) check at 50 mins whether a skewer inserted into the centre comes out clean or with a few moist crumbs. If still mixture on skewer, cook for around 10 mins longer.