Preheat the oven to 400F/200C, and line a baking sheet with baking paper.
Cut a 9 inch (23cm) circle out of the pastry, and place it onto the baking sheet. Leaving a ½ inch (1cm) border, prick the pastry all over with a fork.
Peel and core the apples, cut into quarters, and then into thin slices.
Spread the almond butter over the pastry, leaving the rim exposed, and then arrange the apple slices over the top in concentric circles, starting from the outside and working in.
Sprinkle the sugar all over the apples and pastry (including the border).
Bake the tarte for 30 minutes, at which point the apples should be tender and a little scorched, and the border pastry should be puffed up and golden.
To make the sauce, place the sugar, water and rum into a medium sized, heavy based saucepan. Place the pan over a medium heat, and cook, without stirring, until the sugar melts and turns a dark amber.
Remove from the heat, and carefully add the butter and cream, stirring gently until everything is combined - BE CAREFUL, because it will sputter and steam a lot, and steam burns suck.
When it's all combined place it back on the heat, just until it boils, and then you're done!
Serve!
Recipe by The Sugar Hit at http://www.thesugarhit.com/dev/2015/08/almond-apple-tarte-fine-with-rum-caramel.html