Cream together cream cheese and margarine. Add flour and confectioner's sugar.
Chill for 1-2 hours.
Place sweetened condensed milk into a medium pan and place over medium to medium-high
heat, stirring constantly until it starts to bubble.
Add chocolate chips and vanilla extract and mix until smooth. Remove from heat.
Let cool in refrigerator.
Divide the chilled dough into thirds, sprinkle surface with some flour and sugar,
and roll each piece out to 1/4 inch. Try to work as much of the flour and sugar
into the dough as possible - to make a smooth and nonstick consistency.
Place 1/3 of the chocolate mixture in your hand and shape into a cylinder that will fit along
the center of the rolled out dough. Fold over the sides. Seal and tuck in ends.
Place seam side down on a greased cookie sheet.
Bake at 350 for 30 minutes, or until light golden brown. Repeat with remaining dough and chocolate.