Mix together all dry ingredients.

Using either stand mixer with paddle attachment or your fingers, work butter into dry ingredients until streusel forms.

Break up any large pieces and place topping in fridge while you make fruit filling.

Preheat oven to 375 degrees F and lightly butter or grease baking dish.

Add prepared fruit to large bowl. Mix together cornstarch, sugar and nutmeg and evenly sprinkle it over fruit.

Zest lemon directly into bowl and add vanilla extract and pinch of salt. Using spoon or spatula, mix thoroughly.

Add fruit filling to baking dish and spread it out. Sprinkle crumble topping in even layer over top.

Place on baking sheet. Bake for 40–50 minutes, or until crumble is nicely browned and fruit filling is bubbling

Let cool slightly and serve warm with ice cream. Cover and store leftovers in fridge for up to 3 days.