Step 1: Preheat your oven to 425°F (220°C). If using homemade crust, prepare and chill two 9-inch pie crusts.
Step 2: In a large bowl, combine the sliced apples, granulated sugar, brown sugar, all-purpose flour, cinnamon, nutmeg, salt, and lemon juice. Toss gently until the apples are evenly coated.
Step 3: Place one pie crust into a 9-inch pie dish. Pour the apple mixture evenly into the crust. Drizzle the 1/2 cup of caramel sauce over the apples.
Step 4: In a small bowl, combine the toasted shredded coconut, melted butter, and 2 tablespoons of granulated sugar. Set aside for later.
Step 5: Place the second pie crust over the filling. Trim and crimp the edges to seal. Cut several slits in the top crust to allow steam to escape during baking.
Step 6: Bake for 15 minutes at 425°F (220°C). Reduce the oven temperature to 375°F (190°C) and continue baking for another 35-45 minutes, or until the crust is golden brown and the filling is bubbly. If the crust edges brown too quickly, loosely cover them with aluminum foil.
Step 7: During the last 10-15 minutes of baking, carefully remove the pie from the oven and sprinkle the reserved coconut-sugar mixture evenly over the top crust. Return to the oven to finish baking until the coconut is golden brown.
Step 8: Once baked, remove the pie from the oven and place it on a wire rack to cool completely for at least 2-3 hours before slicing and serving. This allows the filling to set properly.