Plum upside down cake in the IDP

John had bought a load of plums at liddle, so I decided to use up some and made this cake.

I used 6 oz of self raising flour, mixed in 2 oz of corn flour, and 1 tea spoon of baking powder. Then I creamed together 8 oz of stork margarine. 7 oz of brown sugar and added two eggs. Fold these two mixtures together with a quarter of a cup of water. Lined a cake tin with a knob of margarine and put parchment paper in lining the tin sprinkled brown sugar on the parchment paper cut plums in half and put them on top of the sugar. Put cake mixture on top of them , put trivet on bottom of instant pot put cake tin on top of that. Put air fryer lid on pressed bake button then timed it for fifty two minutes at 180 centigrade checking the last 10 minutes to see if knife came out clean. It took exactly fifty two minutes. I checked my electric monitor and it cost 6 pence to cook this cake .