Defrost and drain frozen blueberries. Reserve 4 fluid ounces (½ cup) of juice o be used later.
1 ½ Pounds Frozen Blueberries, defrosted and drained
Place cornstarch in a small bowl and dissolve by whisking in 3 fluid ounces (6 tablespoons) of cold water.
3 Tablespoons Cornstarch, 3 Fluid Ounces Cold Water
Put the granulated sugar into a medium saucepan.
5 Tablespoons Granulated Sugar
In a small bowl combine granulated sugar, ground cinnamon and salt.
1 teaspoon Cinnamon, ⅔ Cup Granulated Sugar, 1 teaspoon Salt
Pour blueberry juice into saucepan with granulated sugar. Heat on medium-high heat, stirring occasionally until it begins boiling.
½ Cup Blueberry juice (reserved from defrosted blueberries)
Lower heat to medium. Add cornstarch/water mixture to pan and stir constantly until thick.
Add sugar/cinnamon/salt to pan and stir until sugar is melted.
Remove pan from heat and let slurry cool briefly.
Pour slurry over blueberries and fold until all berries are coated.