Combine chocolate and butter and melt in double boiler.
Add sugar and gas off the flame.
Mix very well. Add egg and mix well.
Add maida, baking powder, and mix well.
Then add chopped nuts and mix well.
Pour this mixture in baking tin and bake in the oven at 160℃ for 25-30 minutes.
Remove from oven and cool completely.
Cut in slices and pour the chocolate sauce on it.
Serve chocolate slice with vanilla icecream.