In a 10-inch skillet, combine chopped apple, maple syrup, pumpkin pie spice, and salt. Cook over medium heat until the apples begin to soften, about 5 minutes. Then, add the cornstarch slurry, stirring constantly. The mixture should only take about 15 seconds to thicken.
2 Small Granny Smith Apples, peeled, cored and chopped into ¼" cubes, ⅓ Cup Maple Syrup, 1 ¼ teaspoon Pumpkin Pie Spice, 1 Pinch Kosher Salt