Preheat your oven to 350°F (175°C). Lightly grease a 12x9-inch baking dish. Peel, core, and slice the apples, arranging them evenly in the prepared dish. Sprinkle the apples generously with cinnamon, ensuring even distribution for maximum flavor.

In a medium mixing bowl, combine the flour and brown sugar. Cut the butter into small cubes and add it to the mixture. Use a pastry cutter or your fingers to blend the butter into the dry ingredients until the texture resembles coarse crumbs. Set aside.

In a separate bowl, whisk together the brown sugar, hot water, and fresh lemon juice until the sugar is fully dissolved. This syrup will add sweetness and a slight tang to the dish, enhancing the flavor of the apples.

Drizzle half of the syrup evenly over the apple slices in the dish. Sprinkle the crumb topping over the apples, covering them completely. Finally, pour the remaining syrup over the topping, ensuring it seeps through to coat the apples and crumble.

Place the assembled dish in the preheated oven. Bake for 1 hour, or until the topping is golden brown and the apples are tender. Allow the dish to cool slightly before serving to let the flavors meld and the syrup thickens.