If you are using juiced orange skin, you should have about 341 gms or so orange skin left over from four medium sized oranges. If youre using whole oranges, zest and juice your oranges, you can save it for another recipe. Fel free to add the zest in the cake recipe.
Place the orange skins in a saucepan and cover with cold water. Bring to the boil, then drain. Repeat once more with fresh cold water. Cover the orange skins with cold water again. Bring to the boil, then reduce the heat and simmer for 15 minutes, or until soft. Drain and set aside to cool.
Blend the cooled orange skins in a food processor or blender until smooth.
Grease and line a cake tin with baking parchment. Preheat the oven to 180°C fan.
In a mixing bowl, whisk the butter and sugar until light and pale.
Add the eggs one at a time, beating well after each addition.
Add the orange paste and mix until combined.
Add the polenta, ground almonds and baking powder. Fold with a spatula until combined and no dry patches remain.
Spoon the mixture into the prepared tin and spread evenly. Bake for 45–50 minutes, or until golden and a skewer inserted into the centre comes out clean.
Leave the cake in the tin for 10–15 minutes, then transfer to a wire rack.
Mix the honey with 20ml boiling water until dissolved.
Pierce small holes over the warm cake with a skewer or toothpick, then brush over the honey syrup and let it soak in.
Scatter with chopped pistachios, if using. Serve plain or with crème fraîche, extra honey and more pistachios.