Hızlı ve kolay soslu portakallı kek

Orange cake - orange sauce
Recipe ingredients :
4 eggs
1 cup of orange juice
1/4 cup of oil
1 tablespoon of vanilla
2 cups of flour
2 tbsp of cornstarch
1 tbsp of baking powder
For the sauce:
cup of orange juice
Half a cup of sugar
1 tbsp butter
Half a cup of cold water
2 tbsp of corn starch