This roasted rhubarb and vanilla crumble is a delightful dessert that combines the tartness of rhubarb with the sweetness of vanilla. The rhubarb is roasted to perfection, bringing out its natural flavors and creating a soft and juicy texture. Topped with a buttery crumble made with oats, flour, and brown sugar, this dessert is the perfect balance of sweet and tangy. Serve it warm with a scoop of vanilla ice cream for a comforting and delicious treat.