Preheat the oven to 200°C / 180°C fan.
Chop the rhubarb into chunks approx 2" long and the strawberries into halves.
Set the strawberries aside for later and place the rhubarb in a large baking dish. I use an oval shaped dish that measures approx 29 x 18cm.
Sprinkle the rhubarb with 40g of the sugar and bake for 20 minutes.
Cut the butter into cubes and place in a large bowl with the flour. Rub the two together with your fingers until the mixture reaches a breadcrumb texture.
Add the ground almonds, remaining sugar, oats and vanilla extract. Stir together thoroughly.
Remove the rhubarb dish from the oven. Add the strawberry halves to the dish and top with the crumble mixture. If desired, sprinkle a little extra sugar over the top.
Bake for 30 minutes.
Serve with your favourite ice cream, cream or custard!