1. 1. Prepare Oranges: Wash the oranges thoroughly. Cut them into quarters, removing any seeds. Do not peel them. This is key for the amazing flavor of your Sicilian Whole Orange Cake.

2. 2. Puree Oranges: Place the quartered oranges into a food processor. Process until a smooth puree forms.

3. 3. Preheat Oven & Prepare Pan: Preheat your oven to 350°F (175°C). Grease and flour a 9-inch bundt pan or a 9×13 inch baking pan.

4. 4. Combine Wet Ingredients: In a large bowl, whisk together the pureed oranges, eggs, oil, and vanilla extract.

5. 5. Combine Dry Ingredients: In a separate medium bowl, whisk together the flour, sugar, baking powder, and salt.

6. 6. Mix Batter: Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Do not overmix. Overmixing can lead to a dense Sicilian Whole Orange Cake.

7. 7. Bake: Pour the batter into your prepared pan. Bake for 40-50 minutes, or until a wooden skewer inserted into the center of the Sicilian Whole Orange Cake comes out clean.

8. 8. Cool: Let the whole orange cake cool in the pan for 10 minutes before inverting it onto a wire rack to cool completely. Dust with powdered sugar if desired. Enjoy your delicious Sicilian Whole Orange Cake!