Peach and Blueberry Crumble with Oat-Walnut topping

Very loosely based on this recipe

Ingredients

Topping:

10 tablespoons unsalted butter, softened, plus more for the baking dish
3/4 cup rolled oats
1 cup all-purpose flour
3/4 cup packed light brown sugar
Pinch of salt
1 cup chopped walnuts

For the Filling:

4 pounds peaches (pitted, peeled and cut into 3/4 inch slices)
2 cups blueberries
3 tablespoons granulated sugar
2.5 tablespoons all-purpose flour
1.5 teaspoon vanilla extract
1/4 tsp freshly grated nutmeg
1/4 tsp ground cinnamon
1/4 tsp salt

2.5 tablespoons cold unsalted butter, cut into small pieces

Method

Preheat the oven to 375 degrees F. Butter a 2-quart shallow baking dish or 10 6-ounce ramekins.

Make the topping: Whisk the oats, flour, brown sugar and salt in a bowl. Stir in the walnuts. Work in the butter with your fingers until evenly moistened.

Make the filling: Peel the apples and cut into 3/4-inch chunks. Toss with the blueberries, granulated sugar, flour, vanilla, nutmeg, cinnamon and salt in a large bowl.

Transfer the filling to the prepared dish or ramekins and dot with butter. Squeeze handfuls of the crumble mixture and scatter on top of the fruit. Bake until golden and bubbly, 40 to 45 minutes.

Let sit 10 minutes before serving. Top with whipped cream if desired.