Preheat oven to 350℉ (180℃)
Defrost and drain frozen berries. Reserve ½ cup of juice.
1 ½ Pounds Mixed Berries, frozen and thawed
Add cornstarch to a small bowl and dissolve by whisking with cold water.
3 Tablespoons Corn Starch, ½ Cup Cold Water (for dissolving corn starch)
Place granulated sugar into a medium-sized saucepan.
5 Tablespoons Granulated Sugar
In a small bowl combine ⅔ cup of sugar, 1 teaspoon of cinnamon and 1 teaspoon of salt. Set aside for later.
1 teaspoon Ground Cinnamon, ⅔ Cup Granulated Sugar, 1 teaspoon Salt
Pour berry juice into saucepan with the granulated sugar. Heat on medium-high heat, stirring occasionally until it begins boiling.
½ Cup Berry juice (reserved from defrosted berries)
Lower heat to medium. Add cornstarch/water mixture to the pan and stir constantly until thick.
Add sugar/cinnamon/salt to the saucepan and stir until sugar is melted.
Remove pan from heat and let the slurry cool briefly.
Pour slurry over berries and fold until all berries are coated.