Take all the cold ingredients directly from the fridge and blend using an electric blender until you achieve a foamy consistency. The cream should be perfectly whipped: be careful not to take it too far as it will turn to butter. For optimum results prepare the foam just before serving or use a siphon.
Cut the apples into matchsticks and pour over the lemon juice.
Boil the water and sugar then add the thinly sliced apple and the zest of the lemon. Cook until soft, add the saffron and remove from the heat. Leave to cool. Add the lemon juice and finely blend, preferably using a hand blender. Keep refrigerated until plating.
Take a glass and create a layer of oat crunch, a layer of foam and a layer of jam, and complete with the apple matchsticks at the top. Serve immediately.