• 5 eggs
• 160 g powdered sugar
• 160 g flour (medium grind)
• 3 tbsp water
• 2 tbsp oil
• 1½ tsp baking powder
• Pinch of salt

This corrected list should give you a fluffy, stable sponge base.

Would you like me to also write out the step-by-step baking method for this sponge cake, or adapt it into a festive child-friendly version with playful toppings?