Place top oven rack in center position and pre-heat oven to 350° F. Grease an 8x8" baking dish and set aside.
Place the apples in a large mixing bowl and toss with fresh lemon juice. Add the maple syrup, apple juice, cinnamon, all spice, thyme leaves, and salt and toss to combine. Set aside.
Combine the topping ingredients in a large mixing bowl. Stir until the oats are thoroughly coated and all ingredients are well combined. Set aside.
Pour the apple mixture into the prepared baking dish and spread into an even layer.
Spread the topping evenly across the top of the apple layer.
Bake in the pre-heated oven for 30 minutes until the top is nicely brown. Cover the dish loosely with aluminum foil to prevent over-browning and continue to bake for another 15-20 minutes or until hot and bubbly!
Remove from the oven and allow to cool for 5-10 minutes.
Serve warm with sugar-free vanilla ice cream or maple whipped cream, if desired.