Rhubarb and Apple Crumble

• 450g rhubarb
• Juice of half a lemon
• 120g dark brown sugar (or any other)
• 300g apples (Bramley or other cooking apple)
• 1 tsp vanilla extract (or 1 vanilla pod)
• 100g dark brown sugar (or any other) plus an extra 10g to go beneath the crumble. 

Topping

• 220g plain flour
• 120g cold salted butter
• 100g demerara sugar (or caster)
• 1 tsp salt
• 1 tsp ground ginger (optional)

First chop the rhubarb into roughly 1cm pieces. Then put in a saucepan and cook on a medium heat with the sugar and the lemon juice. Once all the rhubarb has broken down, and it's is soft and reasonably easy to stir, remove it and put in a baking dish to fill roughly a third. It should still be quite tart, if you don't like this flavour you can use extra sugar (but remember the crumble is very sweet on top).

Now chop the butter into small chunks (use it straight out of the fridge) add them to the flour, sugar, salt and ginger if using, and rub it all between fingers and thumbs. Keep working the crumble until all the lumps of butter have disappeared and the mix resembles dry breadcrumbs. A few very small lumps of butter leftover are fine.

Then slice the apple into small-medium sized slices, removing the skin if you like (or just some of it if you're lazy like me), and lay them out of top of the rhubarb. Use an extra bit of lemon juice (or just wipe the lemon you have squeezed) over the top of the apple slices to stop them going brown. Then add a small layer of dark brown or other sugar and then add the crumble on top. 

Bake for at least an hour at 180 C or until the top is lightly browned. 

Serve with ice cream, cream or custard.