Crumbles are a firm favourite at our house and I’ve been making them for years and years! I always get the best reactions when the crumble is really crunchy. And for that crunchy topping, it’s best to use brown sugar. White sugar is fine, and the crumble texture is a bit lighter. However, I find that it never turns a truly golden colour. I like to mix brown and white sugar together so I get that extra crunch. This also helps to keep the flavour light and not too treacly. Do feel free to experiment for yourself and let us know how you get on!