Put 1cup of sugar in the pan and heat it till caramelized than add half of the butter (100g) and stir put the pineapple on top of it and put aside

Wisk all the rest the butter vanilla zest remaining sugar and the eggs until well blended then add the flour and baking powder

Pour the mixture into the pan containing the caramel and pineapple and bake about 3/4 an hour in a preheated oven 180 degrees

Once it is done flip it and poor all over it the pineapple juice that you reserved from the can that had the pineapple slices