Start by boiling water as per package instructions for both the Berry Blue Jell-O and Strawberry Jell-O. In separate bowls, pour the boiling water over the Jell-O powder for each color, stirring until completely dissolved. Once mixed, pour the blue Jell-O into a baking dish and the red Jell-O into another. Refrigerate for at least 4 hours, or overnight, until fully set and firm to the touch.

In a large mixing bowl, sprinkle the unflavored gelatin over cold water, allowing it to bloom for 5 minutes. After blooming, heat 1.5 cups of boiling water and stir into the gelatin mixture until completely dissolved. Mix in the sweetened condensed milk, creating a creamy base, and let it cool down to room temperature.

Once your colored Jell-O layers are completely set, remove them from the refrigerator. Use a knife to cut each Jell-O layer into cubes, ensuring they are uniform for a neat presentation. Transfer the colorful Jell-O cubes into a 9x13 glass baking dish, layering them evenly.

Gently pour the creamy layer over the Jell-O cubes in the baking dish. Return the dish to the refrigerator and chill overnight to ensure everything sets well and the flavors meld beautifully.

When you're ready to serve, remove the set Jell-O from the refrigerator. Use medium-sized star cookie cutters to cut out star shapes from the vibrant dessert. Arrange them on a colorful platter for a delightful presentation.