Traditional German Onion Cake (Zwiebelkuchen)

This German onion cake is a perfect treat when entertaining guests. Zwiebelkuchen, as this cake is called in German, is a savoury onion tart that is made with sour cream, bacon and onion. In Germany, you will find it at street festivals in early autumn, when the leaves change colour and the vintners have finished their harvest. 

What is German Onion Cake?

German onion cake is a savoury tart or pie.  The pie filling consists of sour cream, onion and bacon. The base is made from a yeast dough, but you can also find versions made from shortcrust pastry 

Zwiebelkuchen is either baked in a round cake tin (which makes cake deeper) or flat in baking trays. 

The recipe shared today is of the flat variety and is called “Zwiebelkuchen vom Blech” (literally translated “Onion Cake on a Tray”) 

What do you call Zwiebelkuchen in English?

Literally translated Zwiebelkuchen means “Onion Cake”. “Zwiebel” is the word for onions in German “Kuchen” the word for cake.

You pronounce Zwiebelkuchen as an English speaker as "TS-WE-BELL-COOK-EN".

Americans sometimes refer to this dish as German Onion Pie, as when baked in a cake tin, it is reminiscent of a savoury onion and bacon pie.

Europeans might be reminded of quiche when baked in a round cake tin. But the French have their own version of this German Onion Quiche and call it “ tarte à l'oignon” The difference is that the french onion tart is also baked with olives and anchovies.

What is the difference between Zwiebelkuchen and Flammkuchen?

Flammkuchen is a flatbread that traditionally is topped with onions and bacon. You bake it at a very hot temperature in the oven. (hence the expression “German pizza”). The filling in Zwiebelkuchen is deeper and moister.   

You add the onions on the flammkuchen raw. Whereas in Ziebelkuchen you slowly fry the onions and so that the flavours turn almost sweet. You can get the traditional Flammkuchen recipe here. 

History of Zwiebelkuchen 

The recipe for Zwiebelkuchen varies between regions in Germany. It is unclear who made the “original'' onion cake. The cake is very common in wine-producing parts of Germany. Bavarian Zwiebelkuchen and Schwäbischer Zwiebelkuchen are the two variations that are the most popular.

In the wine-producing regions in Germany, it is customary to celebrate a festival once the harvesting season is over and the first wines are ready for drinking. These festivals are called “Besen-und Straussenwirstschaften”. They are like pop up wine bars where the vintners sell the wine they made. This custom originates from the time of the Emperor “Karl the Great” who in the 8^th century allowed the vineyards to keep some of the wine they produced for themselves.

How to make German Onion Cake 

This version is called “Zwiebelkuchen vom Blech“ in German. "vom Blech" means baked on a tray. This distinguishes it from the Onion Cakes that you bake in a round cake tin.

Ingredients: 

For the yeast base

• 7 g instant yeast (2 teaspoon or 0,24 oz, 1 pouch)
• 150 ml / 5 fl oz lukewarm milk
• ¼ teaspoon salt
• pinch of sugar 
• 300 g / 11 oz flour

For the onion filling

• 1 kg/ 35 oz onions 
• 200 g / 7 oz bacon (cubed) 
• ¼ ground caraway seeds (you can substitute the caraway seeds with cumin) 
• 400 g/ 14 oz sour cream (you can substitute sour cream with crème fraiche) 
• 3 eggs 
• Salt and pepper to taste

To garnish (optional)

4 tablespoon chopped fresh chives

Zwiebelkuchen Recipe Steps

1. Add the instant yeast and sugar into the lukewarm milk. Mix and leave to rest for 10 minutes. The yeast should activate and you should see little bubbles forming on the surface.
2. Combine the flour and salt in a bowl. Pour in the yeast-milk mixture. Using a stand or hand mixer with a dough hook, knead the dough for about 5 minutes until the dough comes together and pulls away from the sides of the bowl.
3. Lightly grease a large bowl with oil or use nonstick spray. Place the dough in the bowl, turning it to coat all sides in the oil. Cover the bowl with aluminium foil, plastic wrap, or a clean kitchen towel. Allow the dough to rise in a relatively warm environment for 45 minutes.
4. In the meantime we can start with the onion topping. Peel the onions and chop them into thin rings. Cube the bacon.
5. Heat 1 tablespoon of oil in the frying pan and fry the bacon until crispy. Now add the onions and fry them with the bacon on a low to medium heat until translucent. You do not want to hurry up this step, as it will add to the sweetness. Slow cook the onions for about 10 minutes.
6. At the end mix in the caraway seeds. Leave the onion mixture to slightly cool.

7. In a separate bowl mix together the sour cream and eggs. Then add the egg-sour cream mix to the onions and bacon and mix well. Season with salt and pepper to taste. 
8. Preheat the oven to 200°C/ 392°F. Either grease the baking tray with somebutter or line it with baking parchment.
9. Once the dough has risen, knead the dough one last time by hand on a floured surface. Then roll it out to a thin rectangle. Lift the dough into the baking form and press the dough into the corners with your finger to create a small rim. 
10. Pour the onion mixture onto the yeast base Bake in the oven for 35 minutes. 
11. Leave to cool slightly before serving. To garnish sprinkle with fresh cut chives. (optional)

Recipe Variations:

• Use a different cake tin. Instead of a baking tray use a 10 inch round cake tin.
• Use shop bought pizza dough or puff pastry as your base. If you need to save time, this is an effective shortcut to take.
• Vegetarian Onion Cake. To make a vegetarian version of this onion cake, just omit the bacon in the recipe. Instead you can also add in some leeks, to add a different texture of add some grated cheese, such as gouda or cheddar.

How to serve Zwiebelkuchen

This German onion cake is predominantly eaten as a snack, i.e when entertaining guests, as part of a party buffet or at a stall in the market. You can also eat it as a main course. 

You can eat the slices cold or warmed up. 

What to serve with Zwiebelkuchen? 

I like to prepare a green salad as a side dish. This goes well with this healthy onion cake. 

Traditionally you will serve this with a young wine called “Federweisser”. However, a dry Riesling would not be amiss either.

Storage Instructions 

Store any leftover onion cake in an airtight container in the fridge. Consume within three days.

Can I freeze Zwiebelkuchen?

Thankfully yes. Divide it into portions and place it in an airtight container. It can stay frozen up to three months. Defrost at room temperature. If you like to eat it warm, place it in the oven for 5 minutes to crisp up.

More German Streetfood Recipes

• Flammkuchen Recipe
• Bremer (German Fish Sandwich)
• Currywurst
• Frikadellen
• Turkey Schnitzel

This post was first published in January 2014 and updated in July 2021.