Grease the base of a square pan and line with oil/butter.

Line with parchment paper. (I use Oddy uniwraps as I need not grease the parchment plus I can reuse it in my next bake).

Melt the butter and add cocoa. I added the cocoa and melted it in the MW at high for 10 seconds.

Mix well and set aside to cool a bit.

Sift the maida/APF with baking powder, add the walnuts and set aside.

Open the Oreo packets and remove the cream in between the cookies. Discard the cream and use the cookies.

In a big mixing bowl transfer the cocoa and butter mixture, add the eggs and the vanilla essence. Add sugar and mix/beat well.

Add the maida and walnuts mix well.

Transfer the mixture to the prepared pan and spread to the edges.

Line as many cookies as you can I used . (The recipe says 12 slices).

Place in the microwave oven and MW on high for 6 minutes.

Let the dish stand in the oven for 5 minutes before removing from the oven.

Transfer to a cooling rack and let the brownie cool completely.

Using the edges of the parchment remove the brownie.

Slice and serve.

Tastes best with ice cream or whipped cream.