Grease a small rectangle banking tin with butter and line it with parchment paper.
Roughly break oreo biscuits with hands and take them in a chopper/mixer jar and grind to a coarse powder.
Transfer the oreo powder to a wide bowl and add condensed milk and milk. Mix for about 3-4 minutes. You will notice that oreo granules have begun to melt and you will have a smooth batter.
Now add baking powder. Mix well.
Pour the batter into greased baking tin.
Bake in a pre-heated oven at 180 degrees for about 25 minutes. Baking time depends on your convection. We suggest you remain alert after 20 minutes. If brownie does not get ready after 25 minutes, you may bake for a few more minutes.
Insert a toothpick into the middle of the brownie. If it comes out clean, cake is ready. If it doesn’t come out clean, bake for a few more minutes.
Cover with a cloth and let it cool. Once cooled, invert on a plate and remove parchment paper.
Cut into squares and enjoy these yummy oreo brownies.