Homemade Oreo biscuits

100 gm butter
1 cup powder sugar
1 cup flour
1/2 cup cocoa powder
1/2 tsp BP
Few drop vanilla essence
2-3 tbsp milk
Baking time 7-15 minutes
Filling
1 tbsp butter
4 tbsp sugar
2 tbsp cream
Few drop vanilla essence
1 tbsp powder milk