1. Wash the oranges thoroughly. Place them in a pot of water and simmer for 30–40 minutes to soften the peel and reduce bitterness. Let cool completely.

2. Cut the boiled oranges into quarters, remove any seeds, and blend into a smooth purée.

3. Preheat oven to 350°F (175°C). Grease a 9-inch springform pan and line the bottom with parchment paper.

4. In a large mixing bowl or food processor, combine the orange purée, eggs, sugar, vanilla, and olive oil or butter. Blend until smooth.

5. Add almond flour, baking powder, and salt to the wet mixture. Stir or pulse until just combined — don’t overmix.

6. Pour the batter into the prepared pan and smooth the top.

7. Bake for 45–55 minutes until golden and a toothpick comes out clean.

8. Cool in the pan for 10–15 minutes, then transfer to a wire rack. Cool fully before dusting with powdered sugar or glazing.