Here's the recipe for Broken Glass Jell-O I tried from The Food Librarian. It turned out good, but I was hoping it'd be a thicker consistency, more like Jigglers. It turned out thicker than regular Jell-O, but you're still going to need a spoon to eat it the way it was.
I think next time I make it, I'll make it like this:
For each color:
1 – 3oz box of Jell-O
1 envelope gelatin
1 cup boiling water
Mix Jell-O and gelatin, add boiling water. Stir until dissolved. Chill in meat loaf pan. After they're set. Cut into small cubes with a knife that's been run under hot water and arrange in a metal 9x13 pan or Jell-O mold.
(It's easier to get out of metal pans.)
For white stuff:
1 can of condensed milk (NOT the evaporated stuff.)
4 envelopes gelatin
1/2 cup cold water
1 1/2 cups boiling water
Add 1/2 cup cold water to gelatin, wait until it blooms. Add 1 1/2 cups boiling water, stir until it dissolves. Add condensed milk and stir. CHILL but not until it's set, just to about room temp. If it's not chilled enough when you pour it over the other cubes the colors will run. Pour it over the cubed Jell-O and chill overnight.