Start by combining 1 cup of coarsely ground coffee with 4 cups of filtered water in a large jar or pitcher. Stir gently to ensure the grounds are fully submerged. Cover and refrigerate for 12 to 72 hours.

Set up a fine mesh strainer over a large bowl lined with coffee filters or paper towels. Slowly pour the brewed coffee through the strainer, allowing it to filter for about 30 minutes.

Transfer the strained coffee back to the jar or mixing bowl. Add 1 cup of sweetened condensed milk and whisk vigorously until fully blended.

Pour the coffee mixture into popsicle molds, filling each about ¾ full. Insert sticks and freeze for at least 6 hours or overnight.

To release the popsicles, hold the mold under warm running water for about 30 seconds. Gently pull on the sticks to release.