Preheat the oven to 150°C. Toast the almonds on a flat roasting try for 5-7 minutes, shaking the tray occasionally to ensure they toast evenly to a pale gold colour. Toast the oats and honey on a separate tray at the same temperature for 8-10 minutes, stirring occasionally. Set aside and allow to cool. In a mixing bowl, cream the butter and sugar. Sift in the flour until a crumbly consistency is reached, then add the vanilla, cornflakes, toasted almonds and honeyed oats. Lastly add the mint. Set aside until required.
Preheat the oven to 180°C. Melt the butter in a large saucepan over a medium heat but do not allow it to colour, as this will affect the flavour. Using a sharp-pointed vegetable knife, carefully slice along the length of the vanilla bean to expose the seeds and scrape them into the saucepan, along with the bean. Place the feijoas, apples, sugar and cinnamon into the saucepan and cook over a medium heat, stirring occasionally to prevent the fruit from catching, until the feijoas are tender (about 10-15 minutes). Remove the vanilla pod and place the feijoa mix into a 20cm ovenproof dish and cover with the crumble mix. Bake for 20-30 minutes until the crumble turns a rich golden brown.
Remove from the oven and serve with a scoop of ice cream and a drizzle of maple syrup.