Combine caster sugar, flour, oats and almonds, add the soft butter and work through to breadcrumb texture. Reserve until the fruit part of the crumble is made.
Peel, core and dice the apples.
Mix diced apples with diced rhubarb, add 10% sugar to weight of fruit.
Melt the salted butter, add the fruit and begin to soften.
Cover with a lid and turn off heat, allow the residual heat to cook the fruit.
Top with crumble mix and bake at 180°C for 12-15 minutes.
Serve with ice cream or custard, or both.
