Even the name of this rich and flavorful dessert — or actually cake — might not be the most inviting one, the taste surely is. If you are not in a mood for heating the oven in the heat of the summer but want to make a cake anyway, a good old Kalter Hund, aka Hedgehog slice, is a perfect option. Making a keto version of this easy classic is super-easy — you need only three ingredients! Best served with whipped cream and berries on the side, this treat is super-rich and satiating, so a little goes a long way. Take first a tiny serving and then see if your sweet tooth really needs more!
What is Kalter Hund i.e. Hedgehog Slice?
This cake with a fancy name is uncooked and usually rectangle-shaped. It consists of layers of chocolate and cookies. The chocolate part also contains a substantial amount of fat for a softer and easy-to-slice consistency. I’ve seen people using butter, shortening, or coconut fat.
Some prefer to use rice puffs instead of cookies. And some tend to add nuts and fruits or berries. Often the cake has chocolate icing or glaze.
I got familiar with Kalter Hund when I was in Germany — and actually first saw the recipe in German cookbooks. Later, I learned that this cake exists in different countries – with as fancy names as German Kalter Hund (i.e., ‘cold dog’). English-speaking call it Hedgehog Slice, the Swedes call it Radiokaka, and the Danes call it Kiksekage. There are numerous other versions as well in other countries that use crushed cookies instead of whole ones.
Anyway, I got intrigued by the German version. When I found recipes for Kalter Hund from my German cookbooks, I immediately wanted to try out a keto version. It didn’t take too long to create it as the original recipe is so simple. Well, there are plenty of different variations of the traditional version, so I went through some of them to get the best ideas for my Keto Kalter Hund, aka Hedgehog Slice. And here you have it!
How to make the 3-Ingredient Keto Kalter Hund aka Hedgehog Slice
Like said, you need a mere three ingredients to make this keto-friendly dessert: dark chocolate, butter or coconut oil, and keto cookies. The easiest option is to get ready keto cookies — if you happen to find a good-quality brand without any nasty ingredients, that is, without artificial sweeteners, grains, or food additives.
As here in Finland we don’t have commercial keto cookies (except the bakery that stole my cookie recipe and makes and sells them without letting me know!), I make my own keto cookies either using that particular recipe or then this one that makes especially excellent cookies for this dessert — naturally you don’t need to make the filled version but just plain cookies.
I actually omit the lemon zest and add vanilla extract instead. In fact, any of these keto cookie recipes is suitable for this Keto Hedgehog Slice. You might want to use softer cookies rather than crunchy cookies because the cake is easier to slice if you use soft cookies.
You also need dark chocolate. I recommend chocolate with at least 85% cocoa content for lower carbs, but nothing prevents you from using lighter sugar-free chocolate — considering you’ll find one that is low in carbs and is not sweetened with artificial sweeteners or maltitol. Erythritol, stevia, and monk fruit are the best sweeteners. I would be a bit cautious with xylitol, as it does have some calories and carbs, and might raise blood sugar levels in some.
In addition to dark chocolate, you need some fat to make the chocolate deliciously soft and the cake easy to slice. I prefer unsalted grass-fed butter, but you can use extra-virgin coconut oil instead, especially if you don’t consume dairy. Naturally, in that case, your cookies are better to be dairy-free as well.
Anyway, I think the most important thing when making this keto dessert is to let the chocolate and butter (or coconut oil) mixture cool down until room temperature or at least until lukewarm. Like that, the mixture thickens a bit, but it doesn’t solidify completely. When you prepare the cake and if the chocolate mixture is too runny, the cookies you lay to the pan with the chocolate just sink to the bottom of the pan rather than make beautiful layers with the chocolate.
Before serving, let the cake stand some 15 minutes at room temperature for easy slicing.
But let’s take a look at how to prepare this keto treat that is especially fabulous for summertime:
Have a silicone loaf pan ready. Silicone pan works best for this cake as the cake is effortless to remove from it.
Have also some keto cookies ready. The actual amount that you need in the end naturally depends on the cookies and their size. For this cake that you see in the photos, I’ve used 30 square-shaped cookies that are 1 3/4 inches (4.4 cm). For the cake that you see in the video, I’ve used 18 cookies that are 2 1/2 × 1 3/4 inches (6.4 × 4.4 cm) in size. All in all, the amount of cookies was about 5 oz (140 g).
Take 8 oz (230 g) very dark chocolate — or lighter high-quality sugar-free chocolate and place it into a saucepan.
Add 8 oz (230 g) unsalted butter or extra-virgin coconut oil.
Heat the saucepan over the lowest heat, all the time mixing…
…until the ingredients are completely melted. Be extra careful not to burn the chocolate. If you are unsure about your cooking skills, it’s best to melt the chocolate and the fat in a water bath (bain-marie).
Let the chocolate mixture cool until room temperature.
Pour 1/4 of the chocolate mixture into the silicone loaf pan.
Lay cookies into a single layer on top of the chocolate.
Pour another 1/4 of the chocolate mixture over the cookies so that the cookies are completely covered with the chocolate.
Lay another layer cookies on top.
Repeat with the rest of the cookies and the chocolate mixture until you’ve used up all.
Refrigerate at least 6 hours or preferably overnight.
Remove the cake from the pan by turning the pan upside down. Knock carefully the bottom of the pan.
I simply love to pipe some chocolate-flavored whipped cream (i.e., whipped cream where I have added a few drops stevia and some cocoa powder) to decorate the cake. In my opinion, this rich cake cries for some extra whipped cream and berries served on the side.
Serve. Use a sharp knife for slicing.
Here’s the recipe for you to enjoy:
- 8 oz = 230 g very dark chocolate (cocoa content min. 85 %)
- 8 oz = 230 g unsalted grass-fed butter
- about 5 oz = 140 g keto cookies
- Combine the chocolate and the butter in a saucepan. Heat over very low heat, all the time mixing with a spoon, until completely melted. Don’t let burn!
- Remove from the heat and let cool to room temperature.
- Take a silicone loaf pan and pour 1/4 of the chocolate mixture into the pan.
- Lay a layer of cookies on the chocolate.
- Pour another 1/4 of the chocolate mixture on the cookie layer. Ensure that the chocolate completely covers the cookies.
- Add another layer of cookies.
- Continue layering with the rest of the chocolate mixture and cookies. The topmost layer should be a chocolate layer.
- Refrigerate at least 6 hours or overnight.
- Decorate for example with whipped cream and berries. Serve.
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|Nutrition information||In total||Per serving if 12 servings in total|
|Protein||54.2 g||4.5 g|
|Fat||345.6 g||28.8 g|
|Net carbs||55.2 g||4.6 g|
|kcal||3619 kcal||302 kcal|
How to vary the recipe
I adore this simple version, but you can naturally jazz it up in various ways. Here are some ideas:
- Instead of whole keto cookies, use crushed keto cookies. Like that, the cake is easier to slice as well.
- Replace the cookies with whole or crushed low-carb nuts, like hazelnuts, pecans, macadamias, almonds, or walnuts. Coconut flakes work wonderfully, too.
- Add freeze-dried berries to the cake. Don’t add too much, as they are higher in carbs than regular berries. From 1/2 cup (120 ml) crushed freeze-dried raspberries, you’ll get about 7.9 grams net carbs.
- You can adjust the richness of the cake – and naturally, the amount of carbs – with the chocolate you use. The darker the chocolate, the richer the cake, and the lower the carbs.
- Since very dark chocolate is not very sweet, you can get more sweetness from liquid stevia or monk fruit. Add the sweetener to the chocolate and butter mixture before letting it cool.
- Use natural flavorings for different flavor tweaks. It doesn’t have to be always vanilla — try natural orange, peppermint, coconut, cherry, or almond flavorings.
- If you want to glaze the cake, use this 2-Ingredient Dark Chocolate Drip recipe for a stunning drip on the cake.
- Even I prefer simply (chocolate-flavored) whipped cream as frosting for this keto cake, this Low-Carb Marshmallow Fluff Frosting is a creamy, buttery frosting that suits this treat perfectly, so is this Keto Chocolate Buttercream Frosting and this Keto Vanilla Frosting.
This week went mostly to Ketokamu package design and further product development. We finally received new curry powder samples from Foodin and examined carefully which one to choose to our keto vegetable puree soup.
We sent some soup for the owners of Foodin, Lasse and Maria, and they loved the soup! I’m so happy we can use their high-quality products in our soups. For example, all the spices and seasonings and the coconut manna and the Cretan extra-virgin olive oil come from them.
Now, when we got the curry powder decided, we can finally start manufacturing soups! Actually, the first test batches of 750 containers of our vegetable puree soup and another 750 containers of our broccoli puree soup will get ready during next week in Kuopio where Kasvis Galleria prepares the soups for us.
At least Bistro Naapuri here in Tampere will sell those soups at first. We cannot bring them to bigger stores yet as the cardboard covers have stamps for organic ingredients and also the key flag indicating that the products are made here in Finland — and we didn’t get the licenses yet. Well, it’s because of summer and the summer holidays that everything is delayed… Anyway, the official launch for the soups is at the beginning of October, so there is still time left to get the licenses.
I also made some ice cream experiments using this chocolate ice cream as a base for our commercial keto chocolate ice cream experiments and the vanilla ice cream from my Low Sugar, So Simple book as a base for the vanilla ice cream experiments.
There are some keto ice creams on the Finnish market now, but the problem is that either they contain ugly stuff (terrible emulsifiers, harmful thickeners, nasty sweeteners, etc.), or they are rock-hard when you take them from the freezer. You have to let the keto ice cream stand at room temperature some 15 minutes before you can get anything out of it – and then the surface is melted and liquid while the interior is still rock hard…
We will bring really indulgent keto ice creams to the market for next summer. And those will be soft, rich, tasty — without a single harmful ingredient. I’ve developed some excellent recipes that got rave reviews from our core team! And no, they are not rock hard when you take them from the freezer. We solved this consistency issue in purely natural ways!
Our CEO Olli was visiting here in Tampere, where we had meetings every day. Here is Olli working, sitting on our couch, surrounded by our cats Pete and Frieda.