I make crumble from cooked fruit eg. strawberries and rhubard with eyrthitol or xylitol sweetener. I then add a crumble top made of toasted almonds, Almond flour, some butter, sweetener, and flax or chia seeds like Leadinglights has suggested. Bake the mix at 180 for 20 mins. Apple is too sugary so berries and 'rhubarb only.