Your cook time may vary depending on the ripeness of the fruit—the riper the fruit, the shorter the cook time.
Stir together sugar and cornstarch in a medium skillet. Add apples and next 4 ingredients, and bring to a boil over medium-high heat, stirring constantly. Boil 1 minute; reduce heat to medium-low, and simmer, stirring often, 8 to 12 minutes or until apples are tender. Stir in butter.