Take sugar in a pan; add butter, milk. Let the sugar dissolve in milk. Keep aside for 10 mins.
In a bowl, take oatmeal, cocoa, peanut butter, vanilla essence. In this dry mix, add the sugar-milk mix and stir evenly.
Take a spoonful of the batter and flatten it out into round shapes. Put on a platter and chill till set.
Devanshiâs got a sweet treat for you: chocolate, oatmeal and peanut butter refrigerator cookies, no oven required.