Watermelon Swiss Roll

Ingredient (A):
3 egg yolks
3-1/2 tbsp AP Flour
1 tbsp cornstarch
1/4 tsp baking powder
2 tbsp milk
2 tbsp canola/veg oil
1/4 tsp vanilla extract/powder

Ingredients (B):
3 egg whites
3 tbsp fine sugar
1/4 tsp cream of tartar

Green & Red food color
Chocolate rice ~ melon seed
Whipped cream

Directions:

1. Preheat oven at 180 deg.   Line parchment paper on a rectangular pan (10x12x1)
2. Mix (A) into a smooth batter.
3. Whisk egg white & cream of tartar till slightly forthy then gradually spoon in the sugar till finish. Whisk at high speed until stiff peak form.
4. Fold beaten egg white mixture into egg yolk mixture.
5. Spread into 2 bowls with red and green food coloring respectively. In a red batter, add in chocolate rice coated with 1 tsp flour & mix. 
6. Pour the mixture separately into tray carefully. Draw the green line on the green mixture to represent the watermelon skin.
7. Bake for 10-12 minutes until golden brown and springy to touch. While cooking place a piece of greaseproof paper on a cooling tray and sprinkle with powder sugar.
8. When the sponge is cooked remove from oven, tip upside down on sugared paper and carefully remove paper from sponge.
9. Cut off any hard crusty edges. Spread with whipped cream and roll. Leave in paper for a few minutes before serving on a plate.