Pre-heat your oven to 180°c (160°c for fan assisted oven or Gas Mark 4) and generously grease a 7-inch cake tin with some extra butter/margarine. In a small bowl, mix together the soft brown sugar with the 40g of butter/margarine. Evenly spread the mixture to the bottom of your pre-greased cake tin.Take your pineapple rings and gently pat the excess juice off them with a clean cloth. Arrange the pineapple as desired on the bottom of your tin (on top of the sugar/butter mixture). Place half a glace cherry into the middle of each pineapple slice and in any gaps around that you think need filling.Set aside. In a large bowl, cream together the caster sugar and 110g of butter/margarine, until it is light and fluffy.
Add the eggs one at time, ensuring each is mixed through before adding the next. Sift in the flour and gently fold to create a batter.
Spoon the batter into your prepared tin, on top of your pineapple slices, spreading evenly to the edges. Bake in your pre-heated oven for 20-30 minutes until risen, golden and a skewer inserted comes out clean.
Allow the cake to cool in it's tin for a short while. To remove from the tin: run a knife around the edge to loosen the cake from the sides. Next place a plate on top of the cake, before flipping over - the cake should fall out of the tin and onto the plate but you might need to give it a tap if it is being stubborn.
Enjoy whilst still warm with a scoop of ice cream! You should get 6 generous slices, or 8 slightly smaller ones.