BEFORE YOU START Line a 22cm (base measurement) round spring form tin with baking paper on the base only (see comment following), but grease the sides well with either butter or coconut oil. You don???t want to upturn this cake onto a cake rack to cool, or you will lose a lot of the crumble on top, so it is important you line the base of your tin with a single piece of baking paper that extends outside the base of the rim (not trimmed to fit inside the base). By doing this you will be able to unclip the sides of the tin, and use the paper to lift the cake onto a cake rack to cool. Preheat oven to 180 degrees, fan forced and place rack into middle of oven.