In a large saucepan, combine the diced apples, granulated sugar, brown sugar, lemon juice, salt, cinnamon, and apple pie spice.
Bring to a simmer over medium heat and cook for 10 minutes, stirring occasionally.
In a separate small bowl, whisk together the cornstarch and water until smooth.
Pour the cornstarch slurry into the apple mixture and stir until thickened.
Remove from heat and let cool completely.