Preheat oven to 200C. Peel quinces and cut into large chunks. Cut rhubarb into 2cm pieces. Stir together in a microwave-safe baking dish along with the cardamom and the honey. Microwave on high for approximately 10 minutes. Alternatively, cook gently in a saucepan until tender.
While fruit is cooking, stir together remaining ingredients except almonds. Spread across the top of the cooked fruit and sprinkle almonds across the top. Bake in the oven until topping is lightly browned and crunchy (this won't take long so keep an eye on it).