Preheat your oven to 350°F (175°C). Grease a 9-inch baking dish or similar pan. Easy start, big payoff.

In a bowl, toss apples with lemon juice, sugar, cinnamon, nutmeg, and a pinch of salt. The scent already hints at delicious chaos.

Fold in blueberries gently so they don’t turn everything purple. If you’re using frozen berries, don’t thaw them fully—just keep them from turning the dish into a smoothie.

Spread the fruit mixture evenly in the pan. This is the foundation; make it look nice, okay?

In another bowl, mix oats, flour, brown sugar, salt, vanilla, and melted butter until coarse crumbles form. It should look like chunky, sandy sunshine.

Sprinkle the crumble topping over the fruit in an even layer. Pat gently so it sticks, but don’t stampede it flat.

Bake for 40–45 minutes, until the topping is golden brown and the filling is bubbling at the edges. A fork should glide in easily.

Let it cool for about 10 minutes before serving. The filling will thicken a bit as it rests—patience pays off.