Rainbow Gelatin Cubes

My son saw these fun jello squares pictured in one of my cookbooks and he begged me to make them.  He helped me prepare each gelatin layer and was so excited to sample the final product.  He rated the squares a two thumbs up!  This is a time consuming recipe, not one I'll make often, but definitely memorable.  Its a guaranteed kid-pleaser.

RAINBOW GELATIN CUBES

4 pkgs. (3-oz. each) assorted flavored gelatin

6 envelopes unflavored gelatin, divided

5-¾ c boiling water, divided

1 can (14-oz.) sweetened condensed milk

¼ c cold water

In a bowl, combine one package flavored gelatin and one envelope unflavored gelatin. Stir in 1 c boiling water until dissolved. Pour into a 13x9x2-inch dish coated with nonstick cooking spray; refrigerated until almost set but not firm, about 20-25 minutes.

In a bowl, combine the condensed milk and 1 c boiling water. In another bowl, sprinkle two envelopes unflavored gelatin over cold water; let stand for 1 minute. Stir in ¾ c boiling water. Add to the milk mixture. Spoon 1-¼ c of the creamy gelatin mixture over the first flavored gelatin layer. Refrigerate until set but not firm, about 20-25 minutes. Let remaining creamy gelatin mixture remain at room temperature until the last layer is complete.

Repeat from beginning of recipe twice, alternating flavored gelatin with creamy gelatin layers. Chill each layer until set but not firm before pouring next layer on top. Make final flavored gelatin; spoon over top. Refrigerate for several hours after completing last layer. Cut into squares.