
Preheat oven to 375°F (190°C).
Lightly grease a 20 cm (8 inches) baking plate.
In a medium‑sized bowl, mix oat, flour, sugar and cinnamon.
Add butter and cut in using your fingertips until the mixture resembles coarse crumbs. Add pecans or walnuts.
It’s also possible to combine dry ingredients with butter in a food processor and pulse until the mixture has a grainy texture.
Mix blueberries and apples (or pears) with the sugar and flour in a large bowl.
Pour the blueberry and apple (or pear) mixture into a prepared cooking plate. Sprinkle the topping evenly over the fruits.
Bake for about 50 minutes or until apples (or pears) are tender and the topping is golden-brown.
Serve hot with vanilla ice cream or frozen yogurt, if desired.
