Healthier Apple and Rhubarb Crumble

Name: Healthier Apple and Rhubarb Crumble
Cuisine: European, British
Ingredients: For the crumble topping; 100g Doves gluten-free flour or almond flour; 50g gluten-free oats; 50g chopped nuts, pecans or almonds; 50g stevia or xylitol; 100g unsalted butter at room temperature, cut into pieces; For the fruit compote; 350g braeburn apples; 30g unsalted butter; 30g stevia or xylitol; 150g rhubarb (thinly sliced); ¼ tsp ground; Cinnamon; Cream, clotted cream or vanilla ice cream, to serve