Preheat the oven to 190°C C/ 400 F.
Beat butter and WHITWORTHS GOLDEN CASTER SUGAR
Add the eggs one at a time.
Add the lemon zest into the mixture.
Sift the flour and incorporate to the mixture. Add the baking powder and gently mix in.
Spread in a greased 9 inch square pan
Halve the plums and arrange on top cute side up.
Sprinkle all over with WHITWORTHS DEMERARA SUGAR.
Bake in for 30 minutes in hot oven.
Serve warm with ice cream or double cream.