Line the baking mould with parchment paper.
Preheat the oven to 180°C/350°F/gas mark 4.
In a bowl, mix the egg yolks with sugar, orange zest + juice and orange extract. Use an electric mixer and batter until the quantity trebles, and the composition becomes creamy.
Add the ricotta and incorporate using a spatula.
Separately, batter the egg whites with a pinch of salt until they keep the shape when you remove the beaters.
Add the egg whites to the composition and use a spatula to mix slowly from the bottom to the top until nicely incorporated.
Mix the baking powder with the flour. Add it to the composition spoon by spoon while mixing carefully, aiming not to flatten the batter.
Sprinkle uniformly three tablespoons of coconut sugar on the bottom of the baking mould. Cut an orange into 1 cm slices and place them over the sugar. During baking, the oranges will caramelise and infuse the cake with their flavour.
Sprinkle 1-2 tablespoons of semolina over the orange slices to help absorb the excess moisture while baking.
Pour the batter over the oranges and gently level it.
Bake for 50 minutes to one hour until golden brown and perform the toothpick test to check the cake is baked thoroughly. As each oven bakes differently, you might need to cover the mould with a tray for the first 20 minutes to avoid burning. During the first 20 minutes of baking, do not open the oven's door!
When ready, remove the cake from the oven and allow it to cool for 2-3 minutes, then place a large plate/cake stand over the mould, hold firmly and turn it upside down. Wear oven gloves and be careful not to burn your hands during this step!
Let the cake cool completely on a rack, then sprinkle with powdered sugar.
Slice the cake and serve it preferably with a steamy cup of coffee or cappuccino. Enjoy!