NEW ONE!! the XXL cake that will drive everyone crazy !! very easy and delicious there is nothing

NEW ONE!! the XXL cake that will drive everyone crazy !! very easy and very good there is nothing left at the table
✔ Ingredients:
▪️for the dough
420g flour
210g butter
150g sugar
16g baking powder
1 egg
▪️for the cream:
700ml milk
120g sugar
60g cornstarch
vanilla flavoring
400g sour cream
▪️400g plums
▪️ icing sugar