Vegan Plum Crumble with Oats

Name: Vegan Plum Crumble with Oats
Prep time: 10 min
Cook time: 20 min
Total time: 30 min
Cuisine: European, British
Ingredients: 12 ripe plums, stones removed and cut into wedges; 1 teaspoon cornflour (corn starch); 2 tablespoons icing sugar (confectioners sugar); 100g (3/4 cup) plain flour (all-purpose flour); 50g (1/2 cup) porridge oats (rolled oats); 100g (1/2 cup) demerara sugar (or brown sugar); pinch of salt; 100g (6 tbsp) dairy-free butter or spread; 2 tbsp flaked almonds (optional)