Frances's original millionaire banoffee required cooking mashed banana into caramel for 25 minutes at 240-245°F with constant stirring. Mary Berry was 'really worried about the toffee bit not setting because you'd put in banana.' The problem: fresh bananas add significant moisture that prevents caramel from setting properly. The solution is freeze-dried banana powder, which delivers concentrated banana flavor without any added liquid. Simply whisk 2-3 tablespoons into store-bought dulce de leche or Carnation Caramel—the result is a thick, spreadable banana caramel that sets firm enough to slice cleanly. The flavor is actually more intense than fresh banana because freeze-drying concentrates the sugars and aromatics. Look for freeze-dried banana powder at health food shops, baking suppliers, or online. In a pinch, you can blitz freeze-dried banana slices in a spice grinder to make your own powder. This technique works for any no-bake recipe where you want banana flavor in a caramel, cream, or mousse without compromising the set.