Tunisian Orange Cake

Trim the hard ends from the orange, then slice it and remove any seeds. Puree the whole orange, peel and all, in a food processor until smooth.

Add one third of the caster sugar and the olive oil, then continue to blend until everything is well combined and fragrant.

In a large bowl, beat the eggs and the remaining caster sugar with an electric hand mixer for at least five minutes, until the mixture is very pale and fluffy.

Gently fold in half of the sieved flour mixture, followed by the pureed orange and vanilla extract. Then, fold in the remaining flour. Mix just until combined; be careful not to overmix, or the cake can become tough.

Pour the cake mixture into the prepared springform tin and smooth the top. Bake in the preheated oven for 20 minutes.

Reduce the oven temperature to 160 °C / Gas 2 and continue baking for another 30 minutes, or until the cake is golden brown and a skewer inserted into the center comes out clean. Let it cool completely on a wire rack before serving.