Preheat the oven to 180C / 350F

Cut the flesh off the pineapple core to make about 1.5cm slices. Melt the butter in a large (wide) non-stick frying pan until bubbling. Add the sliced pineapple along with the sugar and let it simmer. This will take about 3 minutes.

Add the rum and ignite this with a flame. Allow the alcohol to cook off and the flames to die down. Add the vanilla extract. Cook for a further 2 minutes or so. You want the syrup to start thickening and the pineapples to be firm but cooked through.

When ready, empty the fruit and syrup into a sealed cake tine, or smaller frying pan (skillet). I have a 24cm shallow stainless steel pan that is perfect for tartin (pictured above). Arrange the pieces to cover the entire surface of the pan. There may be some overlap. Place the chilled square of puff pastry on top and stretch it to cover the surface, tucking in an excess pastry at the corners.

Bake in the oven for 20-25 minutes and until the puff pastry is golden brown. I like to cool this to room temperature before tipping it out onto a flat plate. You may need to run a spatula around the inner rim of the tartin to loosen it.