Melting ice cream cakes are ubiquitous on the internet and instagram and for good reason, who doesn’t want that giant feast of indulgence on their dinner table? I knew months and months before the date that for my sprinkle-and-ice cream-loving-girl, this was the perfect choice for her second birthday cake.
I made a practice cake two weeks before her actual birthday party, because you know - I’m that kind of person. That went down pretty smoothly: baked the cake in a sheet pan, punched out 3 6” circles, wrapped them in vanilla buttercream, rolled the cake in sprinkles, dripped it with ganache, put a cakeball on top, more ganache and a giant waffle cone. Bit of sprinkles on that and boom, done. Easy! Check it out:
Of course, this gave me way too much confidence when I made her actual birthday cake. And of course, of course, when it was actually important that it turn out perfect, so many things went wrong. Hello too large cakeball that slumped and flattened one side of the cake. Hello ganache that broke, twice. Hello her party is in 3 hours and my cake is falling apart! Help! Through the process I realized that there is beginner’s luck, and there is actually knowing what you are doing when it comes to a cake with this many parts.
So, for all the bakers out there looking to make a cake that is sprinkle covered and topped with “melting ice cream” this guide is for you. May you only make your cake once and not have any issues at all with it!
melting ice cream cake: devil’s food cake with chocolate ganache filling and double drip
Cake: I made a devil’s food cake but you can do any cake that will give you enough batter to spread into a sheet pan. Devil’s food cake is both a great and frustrating choice for this particular project - it is so so so soft which makes it a fabulous cake to eat, and for the same reason, a total bitch to work with. Having said that, freezing the devil’s cakes before you start frosting them will help reduce the crumb loss and covering the sides in sprinkles will mask any imperfections.
Buttercream: I used vanilla and I’m not one to be bossy about these things but you should use vanilla too! The white cream makes for a great background and let’s the rainbow sprinkles shine. I have tried this with chocolate buttercream and raspberry and neither looked as good as the white vanilla.
Fillings and Ganache: my cake layers were filled with chocolate ganache which complemented the devil’s food cake so well. You needn’t make ganache for the filling, you can just make more buttercream and fill your cake layers with that. Or you may want a white chocolate ganache filling - then make more than what I have below.
Drips: here is where I get to tell you that the lovely double ganache on her final cake was not intentional. my over-sized cake ball, placed on the side of the cake flattened that side within a few hours and I had to quickly remove it, along with a lot of white ganache that had already set. I needed another cake ball, more ganache and a way to disguise all my mishaps. I refilled the part of the cake with buttercream to be at level with the ganache for an even top and this time, made a dark chocolate ganache. You of course, will not be making any of my brilliant mistakes so plan ahead: do you want a white drip and a dark chocolate ganache on top? Or maybe just one? Whatever you choose keep in mind you’ll need more or less of the ganache measurements I have below.
devil’s food chocolate cake
I used a recipe I learned in pastry class, but here is one that is very comparable
2 sticks room temperature butter
3 cups organic or conventional powdered sugar (organic is more expensive, and requires sifting but tends to melt quicker on the tongue)
1 teaspoon vanilla (pure or imitation, depending on your liking)
1/2 teaspoon salt
1 tablespoon whole milk
dark chocolate ganache
5 oz heavy cream, plus 2 oz
5 oz chopped dark chocolate (60-70% cocoa solids), plus 2 oz
for dark chocolate you always want to do a 1:1 ratio of heavy cream to chocolate. i found 5 oz of cream and 5 oz of chopped dark chocolate was enough to fill my layers. if you want to do a double ganache drip (dark and white) like I did for my final cake you’ll need the additional 2 oz of each.
white chocolate ganache
white chocolate has much more liquid in it so it will need less heavy cream when making a ganache. start with about 1:3 ratio. so, 3 oz chopped white chocolate and 1 oz heavy cream. add more cream if the white chocolate is not thinning enough. as you stir see how much you need to add (this varies so much with different brands of white chocolate so a test-as-you-go method is best)
bake cake & make cake ball
Bake your sheet pan chocolate cake. Punch out 3 circles with a 6” ring mold. If you don’t have a ring mold, use a 6” cake circle to guide a paring knife around 3 circles. The paring knife method can be a better choice because molds can break the cake, especially with a cake as delicate and crumbly as devil’s food. Speaking of delicate and crumbly, before you move forward with decorating, wrap your circles in plastic wrap, place in an air-tight container and freeze until you are ready with your buttercream and ganache. Frozen, these are easier to frost. You can make the cake a day or even a few days ahead.
Pulse the rest of the cake in a food processor (except you know, the parts you inevitably snack on!) until it becomes dense and almost spreadable. I found that pulsing this cake was enough to make a cake ball without any frosting but you can add a bit to help it on. Using an ice cream scoop, scoop two half balls and with your palms shape them into one ball. Here is where I advise caution in size - as tempting as it is to make a giant cake ball, don’t. It will be too heavy for the cake and will cause sinkage. A 2’inch diameter ball should do but measure it against your cone (use a sugar cone - waffle cones will make you want to make a bigger ball because of their bigger opening) to see if it will fit. Once you have your ball, wrap it in plastic wrap and stick' it in the fridge. You can make more cakeballs with the rest of the cake if you like.
2. make buttercream
In the bowl of a stand mixer fitted with a flat beater, beat butter until light and fluffy. Sift into the bowl the powdered sugar and beat until combined. Add vanilla, milk and salt and beat until smooth. Buttercream made with organic powdered sugar is typically stiffer and so you’ll need more milk compared to conventional powered sugar, judge by stirring with a spoon. Put buttercream in a piping bag and set aside until you are done making the ganache. Take out your cake layers from the freezer and let thaw for just the time you make the ganache and not anymore.
3. make ganache
There are so many ways to fuck up ganache. I’m going to give you specific instructions and do your best to abide by them. (I tried playing it fast and free with ganache and messed up 3 different batches before I did a load of research and stuck to the letter to make the perfect ganache. Save yourself the trouble and do it right, once!)
First, chop up chocolate into very small chunks. This makes it easier for the heat to get to it and melt it. Or, use wafers which are thin.
Put chocolate into a heatproof bowl and set a wooden spoon next to it.
I only want you to warm your cream once, so do it carefully, because if you try to do it after it has mixed with the chocolate you risk overheating it and breaking the ganache.
In a saucepan, heat the cream until it begins to steam. You’ll see bubbles on the edges and this is when it’s time to take it off. Make sure it is hot but don’t let it boil.
Pour cream into bowl over the chopped chocolate. Use wooden spoon to mix once, barely, just to ensure the cream has gotten under and between the chocolate. Let sit for a couple of minutes and only a couple of minutes.
Much of the chocolate will have melted by now but the rest will need encouragement from your biceps. Stir, stir and stir with your wooden spoon until you get a smooth and shiny ganache. Ganache gets thicker as it cools so don’t wait to move to the next step and assemble.
4. assemble the cake
On a cake board, place your first cake layer face up and pipe a tall-ish border circle around it (don’t make it flat as it will be a border to hold in your ganache). Fill the circle with the ganache. I like to have a thick-ish layer so I spoon until it is at the rim of my piped circle.
Put the second cake layer, also face up. (At this point I look at my cakes - if I haven’t leveled them out I try to stack them in a way that adjusts for any lopsidedness.) Repeat piping and filling with ganache.
Place the third layer face down so you have a level top. Frost the entire cake now in a thin-ish layer of buttercream. This is your crumb coat, the tough part because a lot of the dark crumbs want to come out and dance into your white buttercream (which makes for a gorgeous naked cake but it’s just not what you want here.) Use a scraper to gently remove excess frosting. Level the top with an offset spatula.
Put your cake in the fridge for 15-20 minutes so your crumb coat sets.
Frost your whole cake again in another, thicker layer of buttercream. Refrigerate for about 10 minutes. We don’t want this layer to get too hard because we still want enough stickiness in it so the sprinkles adhere without it being overly messy.
On a sheet of parchment paper pour and spread a 1/4 inch layer of sprinkles in about a 15inch long rectangle. The width needn’t be too wide. I am terrible at following measurements so I just picture how much I’ll need to roll my cake in.
Place a parchment circle on the top of your cake. Hold your cake from the bottom of the cakeboard and from the parchment top with just enough pressure to keep it in place (don’t squish it) - I know, this sounds terrifying, but trust me, the cake will survive - and roll it like a wheel into the sprinkles. You’ll have to do this a few times to cover the cake - or once you have a decent layer, put the cake in one palm and use the other to scoop sprinkles and gently press them into the cake. Once covered, remove the parchment paper from the top of the cake and if need be, smooth out the top with your offset spatula.
Make your white chocolate ganache. Follow the same steps you did for the dark chocolate ganache. Judging by the temperature and thickness of the ganache, you might want to wait for it to cool and thicken a bit to create a good drip. Test it by doing one drip and seeing how it goes. Once you have it at the right temperature, carefully spoon the ganache right at the edge of the cake, one drip stream at a time. Spoon a few tablespoons over the top of the cake and smooth over the top - some of this may drip down too, creating a natural look.
If you are only using the white chocolate ganache, you’ll need to keep moving before the rest of your ganache sets. Get your cake ball and place it in the center of the cake. Drip white ganache over the cake ball - note that a chocolate cake ball does peek through the white ganache but if you are doing the double drip with the chocolate, it won’t matter. If you went with white ganache and a chocolate cake, keep in mind most of the ball will be covered by the cone and sprinkles anyway. Once the ball is covered in ganache, place the cone on top and add some sprinkles on and close to the cake ball.
If you are doing a double drip/double ganache let the white ganache set while you make your second dark chocolate ganache. Once ready place the cake ball on top in the center and and spoon chocolate ganache over it. Some of the ganache might naturally drizzle down but you will likely need to do a few yourself by spooning at the edge. Lastly, place cone on top and some sprinkles.