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
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.
You can, just know the top layer is not as pretty as the bottom, so the presentation is not quite as nice that way!
Yes. I’ve seen sweetened condensed coconut milk at some stores that would probably work here!
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.

Glass Block Holiday Jell-O
Equipment
- Food storage containers
Ingredients
- 4-5 3-ounce packages assorted Jell-O in coordinating colors
- 2 packets unflavored gelatin (¼ ounce, or 2¼-2½ teaspoons)
- 1 14-ounce can sweetened condensed milk
- non-stick cooking spray neutral flavored variety
Instructions
- Spray 4 small food storage containers (like Tupperware/Gladware/Rubbermaid) with non-stick cooking spray. Set aside.
- Bring 5+ cups of water to a boil. Combine 1 cup boiling water with 1 package of Jell-O, stirring until dissolved. Place the dissolved Jell-O in one of the prepared containers. Repeat with the remaining packages of Jell-O. Refrigerate for at least 4 hours, preferable overnight.
- When the Jell-O has set, bring another 1 ½ cups of water to a boil. While the water is heating, sprinkle 2 packets of unflavored gelatin over ½ cup of cold water. Allow to stand for about 4 minutes. When the water is boiling, pour 1 ½ cups boiling water over the dissolved gelatin and stir to combine. Add the sweetened condensed milk and mix well. Allow to come to room temperature.
- Lightly spray a 9×13″ pan with non-stick cooking spray. Carefully cut the colored Jell-O into cubes (right in the containers) and gently dump/scrape into the 9×13″ pan. Toss gently to distribute the colors and spread into an even layer.
- Pour the cooled milk mixture over the colored Jell-O and, if necessary, rearrange some of the colored Jell-O to make sure it is evenly distributed and not sticking out of the white mixture too far.
- Place the 9×13″ pan in the refrigerator and chill overnight. Cut into squares, rectangles, or various shapes with cookie cutters and serve.
Notes
- 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!












Questions & Reviews
Linda–The only concern with putting the lids on the containers is that there will be condensation and it may drip down onto your jello and make it not as pretty. But if you let it cool to room temperature before putting the lids on, the condensation will be minimal.
Hope that helps!
you said you need to put it in the frig in open containers….my frig is hard to find a spot..does it not work if you put lids on and stack the containers? i think its so pretty it will be fun!
Made this yesterday for family night. A few things I learned…
One, the jello cubes only needed about 3-4 hours to set up, after that I could cut them perfectly.
Two, make sure the white mixture is not too warm, otherwise when you pour it over the color cubes it will cause them to melt just a little.
I was able to make this all in one day.
Despite a slight pinkish tinge to the white part, it was a huge hit and the kids and guests were amazed.
So I NEVER usually cook without a recipe, but I've been wanting to make this for Christmas and tonight I decided to get started, but I was too lazy to haul my computer into the kitchen and look up the recipe. So I mixed up the Jell-O according to the directions on the box, put it in un-sprayed plastic containers, popped the lids on, and put them in the fridge.
It was only an hour later, as I was settling into an evening of watching the Twilight movies that I decided to look up the recipe, since I couldn't remember exactly how to do the white part. And that is when I discovered the error of my ways.
*headdesk*
Luckily I have a cupboard full of Jell-O, so I could start all over again, but geez, I felt dumb.
And thus I've learned my lesson: When I'm trying a new dish, I shall never, ever, ever cook without the recipe.
I just linked to this blog from mine- these are just amazing and I can't wait to see more!
This is totally awesome. I just might make this for Christmas dinner with my family. The kids would love it!
Matt and Penny–Yep, you could totally do that! In fact, I almost did that last time except that I couldn't find the larger size.
I was wondering if I could use the bigger boxes of jello and make it using double the water then divide each box into two containers? I want to make one dish for a party and one for home. What do you think? Do I make any sense? Thanks Penny
I made this for my daughter's class Christmas party and they turned out just like your pictures and delicious:) Thanks for the great ideas!
Book girl- One envelope of gelatin is 1/4 ounce, which is about 2 1/4 to 2 1/2 teaspoons