Chocolate Vanilla Castella Cake

Material:
4 egg yolks
1/4 teaspoon salt
1/2 teaspoon vanilla
60 ml milk
50 ml cooking oil
65 grams low protein flour (cake flour)
10 grams cocoa powder
1/2 tablespoon milk

Meringue Ingredients:
4 egg whites
1 teaspoon lemon juice
70 grams sugar

Topping choco chips to taste

Pan size 16x16x7cm
Bake at 150-160°c for 70 minutes