Place the orange in a food processor (without the seeds, of course) and blend thoroughly.

Beat the oil, eggs, the sugar and the blended orange in a stand mixer.

Add the flour and the baking powder.

Pour the batter in a cake pan that you have already brushed with butter and bake in a preheated oven at 180°C for about 45-50 minutes. After 30 minutes of baking you can test if it is ready pushing the tip of a knife vertically through the cake; if it comes out clean, the cake is baked.