In a saucepan over medium heat, combine cherries, water, lemon juice, and sugar. Bring to a boil; reduce heat to low and cook, stirring frequently, for several minutes or until cherries give up their juices and are at desired doneness.
Add cornstarch mixed with a little water and bring to a boil. The filling will thicken almost immediately. Remove from heat, cool slightly and add the extract.
May be used as a topping warm or just like a pie filling once cooled to room temperature. Keeps well for several days in the refrigerator, If stored too long, it may get watery.
Note: 2 cups are about the same as a 21 ounce can of pie filling.
To Freeze:
May be frozen before adding cornstarch, then the cornstarch added after thawing. The amount may be slightly different than the four cups you’ll get after the cornstarch is added; just divide the recipe in half and make sure to label to put the right amount of cornstarch in once thawed. If freezing in a Ziploc, make sure all the air is out. If freezing in a hard container, leave a little space at the top, about half an inch, for expansion. Cover closely with plastic wrap, then lid.