Preheat the oven to 175C (350f)
Generously butter 6 ramekins or dariole moulds. About 10oz in side. Arrange on a baking tray. Because I am a cautious Kate, I like to pop a little disc of non stick baking paper in the bottoms too just to make sure for certain that the fruit won't stick
Lay a slice of pineapple in the bottom of each dish. Use a pastry cutter to help you cut them to the right size.
Then sprinkle over the 50g of dark sugar
To make the cake, add the butter, light soft brown sugar, eggs, flour, salt and vanilla to a food processor and blitz. Once its looking like delicious batter divide it between the ramekins on top of the pineapple.
Alternatively, cream the butter and sugar together with an electric whisk then add the eggs and vanilla. Follow with the flour and salt and mix until smooth.
You need to bake them until they are bouncy to the touch and a tooth pick comes out clean. This should take about 25-30 mins depending on your oven but keep an eye on them.
Remove from the oven and leave to cool for a few minutes before turning them out. If the tops have risen into points, you can level these off with a serrated knife and eat the off cuts. Chefs perks and all that.
To make the fudge sauce simply combine the butter, rum, sugar and lemon juice in a pan and heat over medium heat. Stir until all melted together and fudgey.
Once cool and you're ready to serve, drizzle the cakes with the fudge sauce.