This quick and simple raspberry filling recipe simmers raspberries, sugar, and a little lemon juice.
In a saucepan, combine raspberries, sugar, 3/4 cup water, and lemon juice.
Bring to a boil.
Simmer for 15 to 20 minutes while reducing heat to medium-low.
Remove the saucepan from the heat and pour the contents into a bowl using a fine-mesh strainer.
Refill the saucepan with the mixture.
Add to raspberry mixture after combining remaining water and cornstarch in a bowl and stirring until smooth.
mixture to a boil; cook for 5 minutes, stirring occasionally, until thickened.
Refrigerate the filling for at least 30 minutes.