Sweet Bites: Galaxy Chocolate Mousse Cakes with Mirror Glaze

Decorating Galaxy Mousse Cakes with Mirror Glaze requires creativity and a tolerance for mess!

The Occasion: We made Galaxy Chocolate Mousse Cakes for our recent Pick Your Planet themed dinner party with The Foodies, where they were a big hit. “Out of this world,” our friends said. “We love this dessert to the moon and back!”, and “Seconds, please!”

If this sounds like music to your ears, you should make a batch of Galaxy Chocolate Mousse Cakes for a special occasion such as a birthday, anniversary, or some other fancy affair. 

Let’s face it: this is a show-off endeavor resulting in a look-at-me dessert requiring lots of work, lots of time, and more than a few specialty ingredients and equipment.

Fast, easy, and weeknight-friendly this ain’t.

​Making a batch of Galaxy Chocolate Mousse Cakes is a multi-step, multi-day project. A worthwhile and rewarding one, to be sure! Just know what you're getting into. 

You're going to want an upbeat playlist while working on this project. How about this Pop Planet Playlist? Crank it up!

What Makes it Special? The shiny, mirror glaze with shimmering colors creates a real Wow factor.

It’s loads of fun getting artistic while decorating the cakes. Release your inner Jackson Pollock or Peter Max, perhaps.

Follow the instructions, allow enough time for each step (including chill time for the mousse), and find your zen place about the huge amount of mess that will occur during the final phase.

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The Recipe: There are many recipes and helpful YouTube videos on mirror glaze frosting. Informative and mesmerizing to watch. Do a quick online search and see for yourself. This winning recipe comes from Elizabeth at Sugar Hero – she specializes in dessert recipes for the home cook. Noble work indeed, she has my thanks and admiration!

Our photos and process are shared below – including the magnificent mess! – but you should do yourself a favor and click through to read the Sugar Hero recipe in her own words. The author covers this detailed and complicated process in an accessible, straightforward, yet humorous way. 

Serve With: Fanfare and adulation. You’re going to want oohs and aahs when you present these little wonders to your guests. A little pomp and circumstance. The theme from 2001 A Space Odyssey blasting through the sound system as you enter carrying the dessert would not be inappropriate. 

Let's start with the end in mind -- a few shots of the cosmic cakes in-process and ready to serve. Then we'll backtrack and take you through the steps. For the full recipe, please read/print the original Sugar Hero recipe here. Click on the photos to enlarge them and read the captions.

Galaxy Chocolate Mousse Cakes
Recipe source: Sugar Hero
 
Makes 10 Mousse Cakes
Required equipment: Silicone baking molds in half-sphere shapes, washed and dried

INGREDIENTS:

Brownies:

• 6 ounces unsalted butter
• 8 ounces semi-sweet chocolate, chopped
• 2 large eggs
• 2 teaspoons instant espresso powder, optional
• 2 teaspoons vanilla extract
• 5 ounces granulated sugar (3/4 cup)
• 2 ¼ ounces all-purpose flour (1/2 cup)
• 1 teaspoon baking powder
• ½ teaspoon salt

 
Chocolate Mousse:

• 9 ounces chocolate, chopped or chocolate chips (We used 6 ounces 60% bittersweet and 3 ounces semi-sweet)
• 1 ¾ cups heavy cream, divided
• 1/8 teaspoon salt
• 1 packet unflavored powdered gelatin (1/4 ounce)
• 2 tablespoons cold water

 
Mirror Glaze:

• 3 packets unflavored powdered gelatin (3/4 ounces)
• 9 ounces water, divided use
• 10 ½ ounces granulated sugar (1 ½ cups)
• 7 ounces sweetened condensed milk (1/2 of a standard 14-ounce can)
• 12 ounces real white chocolate, chopped or white chocolate chips
• Gel food coloring (Your choice of colors: we used Blues, Pink, Purple, Yellow, White, Orange, White)

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As always, please click on the photos below to enlarge them and read the captions.

Begin with the brownies, which will form the base of each cake. Prep the oven and the pan (350 F., and a foil-lined 9 X 13 pan, lightly oiled). Melt the butter and chocolate together, then let it cool. Add the eggs, then espresso, vanilla and sugar. Whisk, whisk, whisk! Next add the flour and other dry ingredients. Stir gently, then add to the pan. Bake for about 20 minutes, then cool completely. Use a large cookie cutter to cut out brownie circles. Freeze them until ready for use.

Now let's consider the mousse. Combine chocolate, cream and salt. Alternate between melting and whisking until smooth. Cool the mixture to room temperature. Meanwhile prepare the gelatin and set aside. Using a mixer, whip the cream and set aside. The chocolate should be cool by now, so melt the gelatin and mix it in. Fold in the whipped cream. 

Now it's time for the silicone half-sphere molds. Fill the half-spheres with chocolate mousse to the appropriate level, about a half inch from the top. Top the mousse cups with a frozen brownie round, pressing firmly. Freeze the mousse cakes in their silicone molds until very firm - at least 2 hours, 4-6 hours would be better. 

Once frozen, un-mold the cakes and place them on small cardboard circles for easy handling later on. Store them in the freezer until ready to glaze.  ​

Finally it's time to glaze. This is where the magic happens. (Remember: for the detailed recipe visit Sugar Hero.)  Mix the gelatin and set aside. Cook the water, sugar, and condensed milk, then add the gelatin, whisking until it is incorporated. Add the white chocolate to the pan. Use an immersion blender to melt and smooth the entire mixture. 

Divvy up the glaze into assorted bowls for base and accent colors. Add gel food coloring to the bowls and mix. Now set up a 'creativity play station' where the cakes can be elevated, and the glaze can run off, and the whole mess can be contained. Take the mousse cakes out of the freezer and place them on jars or glasses to raise them off the surface but still provide stability. Take a new bowl and mix one of your base colors with a few drops of the accents colors, give it a swirl, and then pour the mixture over one of the galaxy cakes, making sure that the sides are covered. Keep mixing and swirling until all cakes are covered. You can add edible sprinkles if desired -- we used silver stars. Chill the cakes again before serving. ​

The Verdict: These cosmic mousse cakes are so pretty, is it too much to ask for them to taste good too? NO, not too much, these babies are delicious -- with three variations on chocolate (brownie, mousse, and glaze) how can you go wrong?  

As you can see, this is a capital "P" Project. If you're up for it, I say lean in and embrace the challenge. None of it is especially difficult, there are just so many steps. Please let us know if you decide to try making Galaxy Chocolate Mousse Cakes yourself - we'd love to hear all about it!
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Do you have a favorite "Project" recipe that you've made, or is on your Someday list? Share in the Comments, please!

Want more planetary reading material? Find the recap of our Pick Your Planet dinner party here.