Custard with sponge cake

Ingredients
2 eggs
1 egg white
1/3 cup sugar
1 tsp vanilla
3/4 cup flour
1 tsp baking powder
1 tbsp butter , melted

For custard:
Mixture A
100ml fresh milk
60 gm sugar
50 gm cornflour
1 tsp vanilla
2 drops yellow colour

mixture B
200ml fresh milk
50gm butter
1 yolk
Instructions
1. Whisk eggs and egg white with sugar will thicken. Add flour and baking powder. Add vanilla.  Add melted butter.
2. Mix well and pour into a greased dish. Bake at 220 C for 30 mins or till golden.
3. Meanwhile, Boil 200ml milk , add to mixture A and stir well to smoothness.
4. Add butter and stir again till smooth, remove from heat and add yolk , stir till smooth.
5. Pour over cake and cool. Serve.