• Preheat the oven to 160˚C fan/180˚C/gas mark 4.
• Liberally grease and flour a 25 centimeter/10 inch fluted bundt tin.

Start with the cake:

• Add the eggs, sugar and extra virgin olive oil to a stand mixer bowl.
• Using the paddle attachment, mix on a medium-to-high speed for 8 minutes until the eggs are aerated, pale and doubled in volume.
• In a separate bowl, put the flour, potato starch, baking powder and salt and use a balloon whisk to combine.
• Add half of the flour mixture to the mixer bowl, along with the orange zest and half of the fresh orange juice.
• Combine on a low speed until only a few flour streaks are visible.
• Add the remaining flour and orange juice and mix on low until there are no flour streaks remaining. Use a runner spatula to scrape down the sides and base of the bowl to ensure all the ingredients are well mixed.
• Transfer the batter to the prepared bundt tin.
• Place the tin in the oven on the middle shelf and bake for 30-34 minutes until the top of the song is golden brown and springs back with lightly pressed. Use a skewer to test for doneness and, if it returns little crumbs but no batter, remove from the oven.

Whilst the sponge is baking, make the soaking syrup:

• Add all the ingredients to a pan, place over a medium heat and stir to combine, then bring to the boil.
• Reduce the heat to a simmer and cook for a further 5 minutes until lightly thickened, then remove from the heat and leave to cool.
• Once the sponge has baked, leave to sit in the tin for 5 minutes.
• Carefully turn out onto a large sheet of clingfilm and tightly wrap, then set aside at room temperature for 1 hour.

If you are serving the cake warm:

• Unwrap the sponge and arrange on a serving plate.
• Use a pastry brush to liberally apply the soaking syrup to the tops and side, then loosely cover again with the clingfilm and leave to soak for 30 minutes, before dusting with icing sugar to finish and serve.

If you are serving the cake cold:

• half-unwrap the sponge after 1 hour, apply the soaking syrup and then wrap again.
• Allow the sponge to cool to room temperature before placing it in the fridge.
• Remove the cake from the fridge 2 hours before serving and allow it to come up to room temperature.
• Dust the top with icing sugar and serve.