For the fruit: Preheat the oven to 375˚. Slice the apples into about ½-inch thick wedges; discard core. Toss together the apple slices, sugar, flour, maple syrup, lemon zest, juice, and salt in a large bowl. Set aside.

For the biscuits: Whisk together the flour, brown sugar, baking powder, apple pie spice, and salt in a separate medium bowl. Add the butter then cut it into the flour mixture with a pastry blender or your fingers, until pea-sized clumps form. Pour the milk into the flour mixture and stir with a fork until just combined.

Pour the apple mixture into the prepared baking dish. With a 2-inch trigger-handled ice cream scoop or two spoons, scoop portions of the dough and drop it onto the surface of the apples. (The topping will spread as it bakes.) Sprinkle biscuits all over with turbinado sugar.

Bake until the biscuits are golden brown and the filling is bubbly and thickened, 45 to 55 minutes. Serve warm with salted caramel ice cream.