In a saucepan over medium heat, add cherries, granulated sugar, lemon juice, cornstarch, and cinnamon. Stir to combine.
If your cherries are not very juicy, you may want to add water (from a few tablespoons to ½ cup depending on your fruit) to thin your sauce.
Bring to a boil. Reduce heat to medium-low and cook for 8-10 minutes, or until mixture has thickened (If your mixture is sticking to the pan, turn the heat down to low and add a splash of water). Remove from heat and allow to cool slightly.
Baking into a pie
Preheat oven to 375 degrees Fahrenheit. Place prepared pie crust into an 8 or 9 inch pie pan. Fill with cherry pie filling, then place top pie crust over filling. Pinch the edges closed, then make a slit in the middle of the pie for steam to escape. Optionally, sprinkle with a tablespoon of granulated sugar before baking.
Bake for 45-50 minutes, then remove from oven to cool.
*The amount of sugar can be adjusted to suit your tastes - add as little as ½ cup for a less sweet filling. If using sweet cherries, I recommend reducing the amount of sugar to ⅔ cup or less.
4 cups of pitted cherries weighs about 21 ounces/616 grams
Sweet or tart cherries can be used to make pie filling.
Pie filling can be frozen for up to 3 months in a sealed, freezer safe container. Thaw in the refrigerator overnight before using. Pie filling will thicken when chilled, but will thin out again when heated in the oven.
Pie filling can be made with fresh or frozen cherries. If frozen, thaw before beginning.