In a bowl, mix the sugar and orange zest together first to bring out the orange flavor.

Add the sparkling water, orange juice, vegetable oil,baking powder, vinegar, salt, flour, and hot water. Mix everything well until the batter becomes smooth and combined.

Pour half of the batter into a baking pan. (Optional)

Add the cocoa powder to the remaining batter and mix well. Pour the chocolate batter into the pan too for a marble effect.

Bake in a preheated oven at 180°C (350°F) for about 40 minutes or until fully baked.

Let it cool a little before serving. Enjoy!✨🍊