Glass Block Holiday Jell-o {Festive!}

Glass block holiday Jell-o is the kind of festive, colorful recipe that instantly brightens a holiday table. I love holiday-themed Jell-o recipes like our Layered Jell-O, but waiting for each layer to set before adding the next can be time consuming. The beauty of this version is that all of the colors can be made and allowed to firm up at the same time. Once set, they are sliced into little cubes, tossed together, and then covered in a sweet, creamy sweetened condensed milk gelatin to hold everything together. The end result looks gorgeous sliced into tidy squares or rectangles and stacked on a serving plate. As a bonus, they are particularly appealing to kids who might turn up their noses at other holiday offerings! They will probably like helping to make these as well; I always think the colored blocks look like Lego when they’re all tossed together!

Ingredients and Equipment Needed

This is just a preview of ingredients and method, keep scrolling for full printable recipe.

Ingredients

Assorted Jell-O flavors – You’ll need 4-5 colors in the small, 3-ounce packages. Just pick the colors and flavors you prefer.
Unflavored gelatin – This is what firms up the sweetened condensed milk layer. It’s usually sold in a box of several packets near the other Jell-O. Knox is a common brand name.
Sweetened condensed milk – NOT evaporated milk. The longer sweetened condensed milk sits in your pantry, the more yellow it will appear. Use a freshly purchased can for the brightest white color!
Non-stick cooking spray – This is to help the Jell-o release from the pans. Be sure to use a neutral flavored variety.

Equipment

Food storage containers – Like Tupperware, Rubbermaid, etc. These do not need to all be exactly the same size, they just need to be small enough that about 1 cup of liquid will fill them about 1/4 – 1/2 inch deep.

How to Make Glass Block Holiday Jell-o

Spray 4-5 small food storage containers with a light coating of non-stick cooking spray (depending on how many colors you’re using) and set aside.
Bring some water to a boil. Combine each of the Jell-o packets with 1 cup of boiling water and stir until completely dissolved. Allow to cool for a few minutes. Pour each flavor into one of the prepared containers, transfer to the refrigerator, and allow to set for at least 4 hours, or overnight.
Once set, make the creamy gelatin mixture by combining boiling water with unflavored gelatin and sweetened condensed milk.
When that mixture has cooled to room temperature, spray a 9×13 pan lightly with non-stick cooking spray and set aside.
Pull out your colored Jell-o containers and slice them in a grid right in the pan to create little blocks. Empty them all into your 9×13 pan and gently toss the distribute the colors.
Spread the blocks into an even layer and pour the cooled creamy gelatin mixture over the top. Cover and place in the fridge to firm up for at least 4 hours, or overnight.
Cut into squares or rectangles and stack on a plate when ready to serve!

Storing and Other Tips

Store finished Jell-O, tightly covered, cut or uncut, in the refrigerator and enjoy within 3-5 days for best results.
Don’t worry if your blocks aren’t all the same size, or if they don’t come out of your containers 100% cleanly. Use a silicone scraper to gently pop them out of the food storage containers if necessary. Once they’re all mixed up, you won’t notice the little pieces!
You can also cut this Jell-O with cookie cutters for fun shapes!

Frequently Asked Questions

Can I use sugar-free Jell-O?

Yes! I do not have a replacement for the sweetened-condensed milk, however. If you want to make the entire recipe sugar-free, you may need to experiment with using evaporated milk and a sugar-replacement of your choice in place of sweetened condensed milk for that layer.

Can I just serve it out of the pan instead of cutting into squares?

You can, just know the top layer is not as pretty as the bottom, so the presentation is not quite as nice that way!

Can I make this dairy-free?

Yes. I’ve seen sweetened condensed coconut milk at some stores that would probably work here!

Can I make these ahead of time?

Definitely! Make it all the way through to the end. You could even cut the squares ahead of time. For best results, I would cut them but leave them in the pan until ready to transfer to a serving plate.