Preheat the oven to 350°F/180°C/Gas 4. Grease an 8x8" or a 7x10" baking dish and set it aside.
Place the apples into a large non-reactive bowl and toss with fresh lemon juice. Add maple syrup, apple juice, cinnamon, allspice, thyme leaves (if using), and salt. Toss to combine and set aside.
Place the topping ingredients into a separate bowl and stir until all the ingredients are well combined. Set the bowl aside.
Pour the apple mixture into the prepared baking dish and spread it into an even layer. Spread the topping over the apples in an even layer.
Place the apple crumble in the oven and bake for 30 minutes.
After 30 minutes, cover the crumble with aluminum foil and continue to bake for a further 15-20 minutes or until the apple crumble is bubbling.
Remove the crumble from the oven and set aside to cool for 5-10 minutes. Serve warm with some vanilla ice cream or freshly whipped cream, if desired. Enjoy!