Galaxy Cookie Bars

Galaxy Cookie Bars are a fun, colorful dessert inspired by space themes. They resemble sugar cookie bars but are denser and sweeter, making them a delightful treat for kids and adults alike.

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UPDATED: 9/9/2024

What is it about outer space that is so fascinating to us?  Maybe it’s the idea of the unknown or just the thought that there are things out there that we haven’t seen, but know they are there, like giant stars and black holes.  From a young age, I remember learning about the planets, moon, stars and galaxies and finding it all so interesting.

My kids are getting to the age where they are experiencing the same wonder and it’s been fun to relearn with them.  I even got to tell my kids about how “when I was a kid, we had nine planets”.  Talk about feeling old!

[“Back in my day, we had 9 planets” SVG cut file]

These bars look like a sugar cookie bar, but are a little sweeter and more dense like a brownie, without being over the top (although they are buttery *wink*).  As I was making them, my kids thought it was so fun that I was making different colors of batter.  They were very impressed when I pulled it out of the oven. And of course, sprinkles always make desserts better.

Ideas for When to Make and Serve Galaxy Cookie Bars

• Galaxy or spaced themed birthday party
• Glow in the dark themed party
• Trolls themed party
• Stargazing party
• Movie night: Any space movie (Galaxy Quest, Star Trek, Stargate, etc)

What You’ll Need

Scroll down to the recipe card below this post for ingredient quantities, full instructions and tips for success.

Galaxy Cookie Bars

Butter – I’ve used both salted and unsalted butter when making galaxy bars.

White Sugar

Vanilla

Eggs

Flour – I use all purpose flour for this recipe. Using alternative flours may affect the texture.

Milk – Using milk helps make the batter just a little smoother. I use whole milk for this recipe but 2% works too.

Powdered Sugar

Food Coloring – I highly recommend using gel food coloring. You will have more vibrant colors in your batter and you won’t have to use as much food coloring to achieve it. In this recipe I use a neon set of food coloring.

Gold Sprinkles – Optional but they definitely make these bars more fun! They are also great to have on hand when we make rainbow pancakes for St. Patrick’s Day.

Recommended Baking Supplies

• Hand mixer or stand mixer
• Glass mixing bowl
• Metal baking pan: 9×13 is recommended
• Standard measuring cups and spoons
• Small cookie scoop

How to Make Galaxy Cookie Bars

Here’s what you’ll need to make your own galaxy cookie bars:

Preheat the over to 350 degrees F. Grab your 9×13 pan, line it with tin foil and spray with cooking spray. 

Add your butter and sugar to a bowl.  Cream the butter and sugar together with a mixer until light and fluffy. (If you didn’t have time to soften your butter ahead of time (guilty), you can always put it in the microwave for about 20 seconds to soften it.  You don’t want to melt it.)

Add the eggs and vanilla and beat until well mixed.  Then, add the flour, milk and powdered sugar.  Start with 1 Tbsp of milk.  Because you will be adding coloring, you don’t want to add too much milk, as the batter isn’t supposed to be runny.

Once everything is mixed together, divide the batter up into four bowls as evenly as possible.  Add a few drops of food coloring to 3 of the bowls and mix well.  I used neon food coloring so I didn’t have to mix any colors together to get the blue, purple and pink.

Drop each color of batter by large tablespoonfuls randomly into the pan.

*PRO TIP* Use a small cookie scoop with a spring lever to distribute the colored battered throughout the pan.

Use the back of a spoon or a silicone spatula to carefully press the batter into the pan and swirl it around.  Don’t do too much, otherwise you’ll end up with a muddy color instead of cool galaxy swirls.

Bake for 22-25 minutes at 325 degrees F.  You’ll know it’s ready when the edges are slightly brown.  Remove and let cool before cutting into squares.  Sprinkle the gold sprinkles on top and enjoy!

Tips for Success

• Use a tin foil sling. Lining your pan with tin foil is a great way to make clean up faster and easier. Plus, it creates “handles” for you to remove the bars from the pan. This makes cutting the bars and serving them super easy. Spraying your baking pan with cooking spray after adding the tin foil will help prevent the bars from sticking.
• Don’t overbake. Bars can dry out quickly from overbaking so starting your timer with a little less time is a good way to keep an eye on them. Use a toothpick to check for doneness. It should not come out with batter sticking to it which would indicate the bars aren’t done. But it also shouldn’t come out completely clean. A few crumbs sticking to the toothpick is fine. Because your pan is still hot when you remove the bars from the oven, remember that the bars will continue baking for a bit longer. The bars will still taste good even if they get overbaked. But they may not taste fresh for as long since they started out drier.
• Cool completely. Letting the galaxy cookie bars cool completely will make them easier to remove from the pan. It will also make it easier to cut and serve them.

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Recipe FAQ’s

Can I use a different size pan?

If you’d like thicker bars, you could used a square pan, such as an 8×8 or 9×9. You will need to bake the bars for longer. I’d start by adding 2-3 minutes and checking with a toothpick for doneness.

Can I substitute the all purpose flour with an alternative flour?

I have not used other flours in this particular recipe. Using a flour other than all purpose flour will affect the taste and texture of the bars. If you give it a try, please let me know in the comments!

What is the best way to store the bars?

The best way to store these galaxy cookie bars is in an airtight container or zip top bag. They will be good for 3-5 days. Another option is to buy a 9×13 pan with a lid so you can store the bars in the same pan they were baked in.

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