Place 2/3 cup sweetened condensed milk in a bowl or measuring pitcher. Pour the hot coffee over the top and stir until blended. Allow the coffee to cool for a few minutes.
Carefully pour the Vietnamese coffee into 12 popsicle molds, 2/3-3/4 full. Place in the freezer and freeze until slushy, about 1-2 hours.
Mix the heavy cream with 3 tablespoons sweetened condensed milk and vanilla. Pull the Popsicle out of the freezer.
Pour 1-2 tablespoons of cream over the top of each pop and add a popsicle stick to the middle. Return to the freezer and freeze until hard.
To remove from the molds: Fill the sink with warm water and dip the bottoms of the molds in the warm water for 30+ seconds. Pull the sticks straight up, don't turn or twist them. *Although I love the look of wooden popsicle sticks, the molds that come with plastic sticks (with holes throughout the sticks) are easiest to un-mold. Eat immediately, or place in freezer bags and return to the freezer.