This recipe came from the Eagle Brand web site. It's great for sliced apples, or it can be poured over ice cream.
Pour the milk into top of double boiler; place over boiling water. Over low heat (almost lowest setting), simmer 1 to 1-1/2 hours or until thick and caramel-colored, stirring occasionally. Beat until smooth.
NOTE: On 2nd to lowest setting, this took about 90 minutes to 2 hours.