Fold a 45 cm (18 in) long rectangle of aluminum foil into triangles until you have a triangle with a longest side of 10-12 cm (4-5 in). Form this triangle into a cone. Make as many aluminum cones as you want.
2. Step
Cut a sheet of puff pastry into 2.5 cm (1 inch) strips.
3. Step
Wrap the pastry around an aluminum cone so that it overlaps by about 1 cm (⅓ inch). Press the tail of the pastry onto itself so that it sticks.
4. Step
Lay this seam face down on a baking sheet and brush with egg wash. Bake for 18-20 minutes at 180°C (350°F).
5. Step
Whip the double cream. Reserve 2-3 large scoops of whipped cream.
6. Step
Mix the remaining whipped cream with the toffee sauce.
7. Step
Scoop mixture into a plastic bag for piping.
8. Step
Peel and slice banana.
9. Step
Remove aluminum cone.
10. Step
Pipe cones by alternating 2 cm (1 in) of toffee cream and 1 slice of banana. Top with a swirl of reserved cream and a vertical banana slice.
