i. 2 (3-ounce) boxes strawberry Jello
ii. 2 (3-ounce) boxes berry blue Jello
iii. 1 (14-ounce) can sweetened condensed milk
iv. 4 (0.25-ounce) envelopes unflavored gelatin (i.e. Knox)
v. Boiling water
i. Spray an 8-inch or 9-inch square baking pan with nonstick cooking spray.
ii. In a small bowl, stir together 1 box of the strawberry Jello, ½ an envelope of the Knox gelatin and 1 cup of the boiling water, ensuring everything has dissolved. Pour into the prepared pan and place in the refrigerator to set, about 15 minutes.
iii. Meanwhile, in a medium bowl, stir together the sweetened condensed milk and 1 cup boiling water. In a separate small bowl, sprinkle 2 envelopes of the unflavored gelatin over ½ cup cold water. Allow to sit for 5 minutes. Add ½ cup boiling water to the unflavored gelatin mixture and stir to dissolve. Pour into the sweetened condensed milk mixture and stir to combine.
iv. Once the red layer is set, pour 1 cup of the milk mixture over the red layer. Place in the refrigerator for at least 15 minutes.
v. Repeat the layers, alternating the red and blue between the white layers, with blue being your last layer. Ensure that the colored Jello mixtures cool to room temperature before pouring over the previous set layer.
vi. Once all of the layers have been poured, refrigerate for at least 4 hours. When ready to serve, run a thin knife around the edges of the pan and turn the Jello out onto a cutting board. Cut into squares and serve, refrigerating any leftovers.