Mix 3/4 cups coffee with 1 tsp of sweetened condensed milk and pour into the bottom of each popsicle. Do not pour too much, the bottom of the stick should not touch the cold brew layer.
Freeze for 5 hours, then remove from the freezer and take the sticks out of the molds. Take the base cups off of the popsicle sticks.
Mix 1 cup of cold brew with 1 tbsp of sweetened condensed milk. Pour the coffee mixture into the molds (the layer should be around 1 inch thick).
Stretch cling wrap over the base of the molds and poke holes into the top with a knife. Insert the sticks into the cling wrap.
Freeze for 6 hours until frozen, then mix 1 cup of coffee with 2 tbsp of sweetened condensed milk. Cut the cling wrap away with scissors and pour this coffee mixture into the molds until full. Freeze overnight (or 8 hours) and remove from the molds by running them under hot water.