Spray a 9x13 baking dish lightly with cooking spray.

In a small bowl combine the grape jell-o with 1 teaspoon of unflavored gelatin and 1 cup of boiling water. Mix until all the gelatin is dissolved. Pour in the prepared pan and refrigerate for 20-30 minutes until fully set.

Meanwhile, combine 2 teaspoons of unflavored gelatin (1 packet) with 1 cup of boiling water until the gelatin is dissolved. Mix in ⅔ cup of sweetened condensed milk (about half a can). Let cool while the purple jell-o sets. Also prepare the next color of jell-o the same way the grape jell-o was prepared so it can cool.

Once the grape jell-o is set and the milk jell-o has cooled, pour ½ cup of milk jell-o over the grape jell-o. You may need to tilt the dish to help it spread and cover the whole thing. You may also pour the milk jell-o onto the back of a spoon as you pour it over the grape jell-o so it doesn’t create craters in it. Chill in the fridge for 20-30 minutes, until completely set.

Repeat steps 2-4 with the remaining flavors, alternating the colored jell-o with the milk jell-o. As needed prepare the second half of the milk jell-o in the same manner as the first half. Avoid making it all at once, otherwise it will start setting up before it can all be poured between the layers. If it does start setting up, gently heat for 10-15 seconds in the microwave and stir well until liquid. Avoid heating too much because you will have to wait for it to cool down again.

Once all the layers have been made, cut into 1-2 inch squares and serve. For easy release from the baking dish, carefully run hot water over the bottom of the dish for about 10-15 seconds.