To prepare the pineapple, slice off the top and bottom, then stand it on a board and slice off the skin, removing the ‘eyes’ too. Turn the pineapple on its side and cut into 6–8 thick rounds. Remove the core from each round, using a small plain cutter or a small, sharp knife. Lay the pineapple slices in a shallow tray.
Put the sugar, cinnamon, allspice, rum, vanilla seeds and butter into a small saucepan and stir over a medium heat for about 5 minutes, until the butter is melted and the sugar dissolved. Pour this syrup over the pineapple and leave to macerate for 30 minutes.
Preheat the oven to 190°C/Fan 170°C/Gas 5. Line two baking sheets with baking parchment.
To make the ginger nut biscuits, beat the butter and sugar together in a large bowl until light and fluffy. Add the golden syrup and beat until evenly combined. Sift the flour, bicarbonate of soda and ground ginger together over the mixture and mix briefly until it just
comes together to form a dough.
Transfer the dough to a lightly floured surface and roll out to a 3mm thickness. Using a 6cm plain cutter, cut out 20 rounds and lay on the lined baking sheets. Bake for 10–12 minutes, rotating the trays and swapping them over on the shelves halfway through
cooking. Remove and leave to cool on the trays.
When ready to serve, heat a griddle pan over a medium heat. Lift the pineapple slices out of the marinade onto a plate. Pour the marinade into a small saucepan and bring to a simmer over a high heat.