Start by spraying a 13x9 inch pan with non-stick cooking spray.  You'll also want to be sure you have a level space in your freezer. Lay out 7 bowls (4 large & 3 small) 

Gather 7 bowls, 4 large and 3 small. Place 3oz of red Jello in one large bowl, blue Jello in the second and 1 package of unflavored gelatin the third large bowl.  Pour a cup of boiling water into each bowl and stir until gelatin dissolves completely. 

Combine the remaining boiled water (1 ¼ cups) with 2 packages of the unflavored gelatin. Stir until completely dissolved, add sweetened condensed milk and mix well.

Divide sweetened condensed mixture evenly between the 3 small bowls and set aside.

Pour one of the bowls of blue Jello into the bottom of your pan and freeze for 5 minutes.

Pour one bowl of white gelatin mixture over the blue and freeze for 10 more minutes.

Continue alternating the red, white and blue Jello to create a striped pattern. Freeze for 5 minutes after each of the colored layers and 10 minutes after each of the white layers.

Once all your layers have been poured into the pan, place it in the refrigerator for at least 3 hours or until it’s completely set.

To serve, cut layered Jello into 24 equal cubes.

Cover the pan with plastic wrap or place cubes in an airtight container. Refrigerate until ready to serve, then enjoy all the oohs and ahhs from everyone that is super impressed with your patriotic dessert.