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
um… am I the only one that thinks they look like soap? Truth be told, I've always wanted to bite into those fancy bars. I think I'm going to like this dessert.
My kids would love this! How simple and what fun!! My 3 year old has discovered the wonders of jello and has been on a jello kick for the past two days so I may have to make some for him today.
For those looking to substitute the sweetened condensed milk, I wonder if maybe coconut milk might be a good. It's sooo yummy!
amazing! These sound easier to make once you explained the process then what I first thought by looking at the first picture.I must try these. My kids will freak out!
oh wow! I think I just found my new holiday desert for gatherings! The kids (and grown ups) are going to love these this year. Thanks so much.
Jenn–Yep, I bet you could totally do that. The good thing about this Jello is that it is naturally stiff, so you don't have to worry quite so much about the massive potential Jello mess–the texture is more like Jello Jigglers.
Lizzie–What if you replaced the sweetened condensed milk with pear juice or white grape juice concentrate? That way, you could still get some flavor without having the s.c. milk.
Jen- that would be fine. Or really, for a classroom party it might be easier to have it cut into small squares on a serving tray all ready to be picked up by little fingers. That is, if there's a way to keep it cold until then. If not, sure, just leave it in the pan.
Lizzie- it's sweetened condensed milk! Does your hubby know that's sooo different (taste wise) than a glass of milk? lol. Sorry, I just can't imagine a life without sweetened condensed milk! Plain gelatin is flavorless so I definitely wouldn't do that. I suppose you could just use regular jello in a fairly light color, but it definitely wouldn't be as pretty. You could also probably substitute a light colored fruit juice, but I can't guarantee the quantities are going to be right for the firmness you need because we've never played around with it.
question – do you have to do the condensed milk? my husband loves jello, but doesnt drink milk…. and if he thinks that there is anything RELATED to milk in it, he won't eat it, lol!!! could you do the unflavored gelatin alone, no condensed milk and make the bars clear? i mean i dont see why you couldnt do it that way, i just wondered if the condensed milk adds some special texture or flavor that can not be done without. thanks!
We are lactose intolerant in my house so dairy milk regardless of its preparation is a no no in my house . I bet you could use coconut milk, or coconut cream. Coconut cream is pretty close to the same consistency as condensed milk and since you use coconut cream to make pina colada Id be willing to be that its plenty sweet enough. Its worth a try…i think maybe ill give it a shot and see what happens.
Lizzie, will your husband eat imitation whipped topping ? In the 50’s and 60’s my mother made “Stained Glass” dessert with Jello cubes mixed with thawed, (previously frozen) whipped topping just before serving. It also was delish!
The topping is carefully folded into the Jello cubes and served with a large spoon.
do you all think if leaving in pan and then cutting as needed would be okay?
I have a 13×9 pan that has a lid and came in an insulated carrier with a hot/cold pack. this way it would stay cold at school during the party?
or do you have any suggestions in how to keep it cold, and not messy for serving purposes at a classroom party?
Thanks for the suggestion! My daughter is out of school until January 4 (darn year-round school!) and this would be a perfect activity to keep her busy. And it's just so darn pretty!