Slice the apples in half from top to bottom. Remove the core and slice the apples very thinly.
Squeeze the lemon into a large bowl of water. Place the sliced apples in the water and microwave for 5 minutes until slightly tender. Drain the apples.
Preheat the oven to 180°C/350°F/Gas 4. Place the pastry roll on a floured surface and slightly flatten with a rolling pin. Cut each pastry into 6 equal slices. Spread half a tablespoon of salted caramel sauce on each slice of pastry. Warm up the caramel sauce in the microwave beforehand for a few seconds if necessary to make it easily spreadable.
Place about 7 to 9 apple slices along the pastry slice, on the top half of the slice. Fold the pastry in half to cover the apples. Roll the pastry and apples to create a rose and place in a muffin tin lightly greased with butter. Bake for 40 minutes.