2 cups fresh or frozen blueberries
1/2 cup water
1/2 cup granulated sugar
2 tablespoons fresh lemon juice
2 tablespoons cornstarch, mixed with 2 tablespoons cold water
1/2 teaspoon vanilla extract
Zest of 1 lemon (about 1 tablespoon), optional
In a medium saucepan over medium heat, combine the blueberries, 1/2 cup of water, sugar and lemon juice. Stir frequently, and bring to a low boil.
In a small bowl, whisk the cornstarch with 2 tablespoons of cold water.
Slowly stir the cornstarch into the blueberries, taking care not to crush the blueberries. Simmer until the homemade blueberry sauce is thick enough to coat the back of a metal spoon, about 5 minutes.
Remove from heat and gently stir in vanilla and lemon zest.