Spray an 8 x 8 baking dish with non stick cooking spray.

In a saucepan, bring 2 & 3/4 cups of water to a boil, then turn off the heat.

Pour the strawberry Jell-0 into a large bowl, add 2 cups of boiling water and stir until dissolved.

Pour the strawberry mixture into the prepared pan and place in the refrigerator for 2 hours.

In another bowl add 1/4 cup cold water. Sprinkle unflavored gelatin packet over the top and let stand for several minutes.

Stir in the 3/4 cups boiling water and sweetened condensed milk until well combined. Allow to cool.

Invert the strawberry Jell-O pan onto a cutting board or wax paper.

With a heart shaped cookie cutter, cut hearts out of the jello. Cut as many as you can fit, but you may not use all of them in the next step.

Spray the baking dish with cooking spray again.

Arrange the hearts in the pan being careful to leave room for white in between each.

Pour the condensed milk mixture around the hearts and place in the refrigerator for several hours until firm.

Remove from pan and cut into squares.