Preheat oven to 340f,
Grease a 8x8 square baking tin with oil and line it with an over hang of baking paper.
Melt butter and chocolate in a heatproof bowl over a double boiler or in the microwave.
Add sugar & warm milk. Stir with a whisk until sugar is dissolved.
Add the dry ingredients (flour, cocoa powder, corn starch, baking powder & salt) mix with a whisk until the batter is smooth.
Add chocolate chips and chopped Oreos.
Pour brownie batter into the prepared baking tin.
Top it with Oreo cookies and bake for 25-30 min or until it is risen evenly from all sides and the center.
Add some more chocolate chips if desired on baked brownie, let it cool completely in the baking tin. Portion with a warm knife and Enjoy!
