German Poppy Seed Cake (Mohnkuchen)

Recently, I looked around to discover that Christmas had well and truly ended and therefore all the treats that my grandmother brought were but distant, happy memories. That meant I had a house without a cake in it, and what am I meant to do with that? Clearly, it was time for me to start baking again.

I had ordered a package of poppy seeds a while ago with the intention of making some kind of baked good, but I couldn’t decide which. My grandmother makes poppy seed bread and poppy seed pudding, both delicious options, but I really wanted to try something new. 

Then inspiration struck when, over the holidays, my father, mother, and grandmother were reminiscing over a poppy seed cake that a family friend used to make. That cake was two layers, absolutely packed with poppy seeds, and covered in a chocolate ganache-esque frosting unlike any other. The only problem was that we had no recipe, so of course that was the cake I chose to make. 

The cake itself was quite simple to make and, coincidentally, gluten free. I chose to make it a single layer cake, just because there are only four of us in the house, but it could easily be doubled for a special occasion. The frosting, on the other hand, nearly broke me. As you can see below, the recipe my mother had jotted down from her friend on the phone many years ago was less than clear, especially where it completely fails to mention what to do with the butter, which basically meant I just had to guess…and I guessed wrong. 

I added the butter at the end, the way one does in some buttercreams, but the butter would not incorporate so I ended up with a lumpy, oily, separated mess. I tried every fix in the book: reheating it, beating it, chilling it – nothing worked. Fast forward to me crying on the couch because I had wasted nice ingredients and ended up with a frosting I just could not fix. 

Luckily, my beautiful sister saved the day and hypothesized through research that the chocolate had seized, which usually occurs when water gets into melted chocolate. It can also occur when there is not enough liquid, such as when you are making a ganache and do not have enough hot cream to melt all the chocolate. 

She suggested heating a little bit of my disaster frosting in a double boiler and slowly adding cream to it to see if it would come out smooth and, miracle of miracles, after some whisking, it did. We then slowly added the rest of the frosting to the double boiler along with splashes of cream until it came together into a smooth, glossy, thick pudding-like consistency. 

My best guess for why the frosting did not work originally is that because the butter I added at the end was not room temperature, it was much cooler than the heated chocolate/egg mixture, and therefore the high water content in the cold butter caused the chocolate to seize. After checking with my grandma who then called her friend, who invented the recipe, I found out that she adds small pieces of room temperature butter to the mixture at the end. However, it is still quite finicky, so at least now I know how to fix the frosting should it seize again, which, let’s face it, is not unlikely. 

And the saved frosting is absolutely delicious. It turns out I forgot that the original recipe was actually for a two layer cake, so I ended up with twice the amount I needed. My family has been using the leftovers in hot chocolate, smeared on digestive biscuits, and straight up licking it off the spoon. It’s that good. 

Recipe:

Ingredients:

For the cake: 

Adapted from: https://www.sweetandspicy.de/saftiger-mohnkuchen/

200g softened butter

90g sugar

1/4 teaspoon salt

6 eggs

200g ground poppy seeds 

Fruit jam of your choosing (I used blackberry)

Method: 

Preheat the oven to 350 degrees 

Butter an 8-inch cake pan and line it with parchment paper.

Grind your poppy seeds in a small food processor or spice grinder until just before paste consistency, and when you start to smell the poppy seeds.

Separate your egg whites and yolks. 

Beat together your egg yolks, butter and sugar in a stand mixer until very light and fluffy, about 5-7 mins, then transfer the mixture to a large mixing bowl.

Clean out your stand mixer bowl thoroughly, and beat the egg whites and salt until you reach stiff peaks. 

Fold the egg whites and poppy seeds into the butter mixture in small batches, alternating between the two until combined. Be gentle so as not to deflate the egg whites too much. 

Pour the mixture into the cake pan and bake for 45-60 minutes. Check after 45 minutes, if a skewer comes out clean, it’s done. 

Allow to cool for 10 minutes before removing from the cake pan, then allow to cool completely on a wire rack before decorating.

For the frosting:

Ingredients: 

2 egg yolks 

1/4 cup sugar 

3.5oz bitter chocolate (I used 70%)

1 stick (1/4lb) of butter, cut into small cubes

Method: 

Place the chocolate in a double boiler and allow to gently melt. 

Meanwhile, beat the yolks and sugar together until lightened in color and place in a double boiler. 

Continue to whisk them together until warm. 

Once warm, and to the chocolate, take the mixture off the heat and whisk to combine. 

Slowly add the soft butter to the mixture, (I find beating it in with a wooden spoon works best) fully incorporating each addition before adding the next. It will seem lumpy, but keep adding the butter. I promise by the last addition of butter, it will miraculously become smooth.  

The mixture should end up with the texture of a thick ganache. 

Assembly: 

Once the cake has cooled completely and the frosting has thickened, spread a layer of jam on top of the cake. Then frost the cake all over. 

Decorate with fruit and nuts as desired. 

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