1. In a saucepan, mix sugar, cornstarch, espresso powder and butter until blended. Stir in milk. Bring to boil over medium heat; cook and stir for 2 minutes or until thickened.
2. Remove mixture from heat, stir in vanilla and cool completely. Stir in condensed milk.
3. In a mixing bowl, beat cream until stiff peaks form; fold into milk mixture. Pour mixture into ice cream mixer and follow manufacturer's instruction's on freezing. If you do not have an ice cream mixer, pour mixture into a 9 inch square pan and freeze for 6 hours or until set, stirring occasionally to prevent the ice cream to become crystallized.