Place top oven rack in the center position and pre-heat oven to 350°F. Grease an 8” x 8” baking dish and set aside.
Place apples in a large bowl and toss with fresh lemon juice. Add maple syrup, apple juice, cinnamon, allspice, thyme leaves, and salt. Toss to combine and set aside.
Combine topping ingredients in a separate bowl and stir until oats are thoroughly coated and all ingredients are well combined. Set aside.
Pour apple mixture into prepared baking dish and spread into an even layer. Spread the topping evenly across the top in a uniform layer, as well.
Place into pre-heated oven and bake for 30 minutes. If the top layer is nicely browned, cover dish loosely with aluminum foil to prevent over-browning. Continue baking for another 15-20 minutes or until the apple crisp is nice and bubbling. Remove from oven and set aside to cool for 5-10 minutes.
Serve warm with vanilla ice cream or whipped cream, if desired.