In large microwaveable bowl combine the CHUNKS, sugar and evaporated milk.
Microwave on high for six, one-minute intervals, stirring after each interval, then for four, 30-second intervals, stirring after each interval (total of 8 minutes).
Mixture will become thick and bubbly.
Add vanilla, stirring well to combine.
Refrigerate mixture until ready to use.
When ready to use, spoon out desired amount and place in glass bowl or cup.
Microwave for 35 to 45 seconds on high, or until fully warmed.