Black Cherry Filling
- 2 pounds frozen black cherries, thawed, drained, and juice reserved
- 1/2 cup sugar
- 3 tablespoons kirsch
- 2 tablespoons cornstarch
Whisk reserved juice, sugar, kirsch, and cornstarch in a small saucepan until smooth. Cook over medium heat, stirring constantly, until mixture is thick enough to coat the back of a spoon, about 8 minutes. Let syrup cool slightly. Combine syrup and cherries in a medium bowl. Refrigerate until ready to use, up to 2 days.