Make sure all ingredients are at room temperature. Preheat the oven to 180°C (convection oven 160°C). Combine the mix with eggs and water. Mix on high speed for 7 to 8 minutes, then mix on low speed for another 2 to 3 minutes. Pour the batter into a greased baking pan, filling it halfway to two-thirds. Bake in the centre of the oven. Do not open the oven during baking. The sponge is ready when it springs back to the touch. Remove from the pan immediately and cool on a wire rack.