The Classic Donauwelle: German 'Danube Wave' Cake

🌍 Cuisine: German
🏷️ Category: Dessert
⏱️ Prep: 45 minutes
🍳 Cook: 30-35 minutes
👥 Serves: 12-15 servings

📝 About This Recipe

Named after the majestic Danube River, the Donauwelle is a show-stopping German classic that features undulating waves of vanilla and chocolate marble cake. Tucked within the batter are tart sour cherries, which are then topped with a silky German buttercream and a signature rippled chocolate ganache. This cake is the perfect balance of fruity tartness, creamy richness, and deep cocoa, making it a staple of every traditional German 'Kaffee und Kuchen' afternoon.

🥗 Ingredients

Marble Cake Base

  • 250 grams Butter (unsalted, softened to room temperature)
  • 200 grams Granulated Sugar
  • 5 large Eggs (at room temperature)
  • 1 teaspoon Vanilla Extract
  • 350 grams All-purpose Flour (sifted)
  • 3 teaspoons Baking Powder
  • 1/4 teaspoon Salt
  • 3 tablespoons Cocoa Powder (unsweetened, high quality)
  • 2 tablespoons Milk (for the dark batter)
  • 700 grams Sour Cherries (jarred, drained thoroughly)

German Buttercream

  • 500 ml Whole Milk
  • 1 package Vanilla Pudding Powder (standard 40g pack or cornstarch equivalent)
  • 100 grams Sugar (for the pudding)
  • 250 grams Butter (unsalted, must be same temperature as pudding)

Chocolate Glaze

  • 200 grams Dark Chocolate (60% cocoa or higher, chopped)
  • 20 grams Coconut Oil (or butter, for shine and easier slicing)

👨‍🍳 Instructions

  1. 1

    Preheat your oven to 180°C (350°F). Grease a deep 9x13 inch (approx. 25x35cm) baking sheet or rectangular springform pan and line the bottom with parchment paper.

  2. 2

    Prepare the pudding for the buttercream first: Whisk the pudding powder and 100g sugar with a splash of the 500ml milk until smooth. Bring the remaining milk to a boil, stir in the mixture, and cook until thickened. Transfer to a bowl, cover the surface directly with plastic wrap to prevent a skin from forming, and let it cool to room temperature.

  3. 3

    In a large bowl, cream the 250g softened butter and 200g sugar until light and fluffy, about 3-5 minutes.

  4. 4

    Add the eggs one at a time, beating well after each addition. Stir in the vanilla extract.

  5. 5

    Sift together the flour, baking powder, and salt. Gradually fold the dry ingredients into the wet mixture until just combined. Do not overmix.

  6. 6

    Spread about two-thirds of the light batter evenly onto the prepared baking sheet.

  7. 7

    Mix the cocoa powder and 2 tablespoons of milk into the remaining one-third of the batter. Spread this chocolate batter carefully over the light batter.

  8. 8

    Distribute the drained sour cherries evenly over the top. Gently press them into the batter; as they sink during baking, they create the 'wave' effect.

  9. 9

    Bake for 30-35 minutes until a toothpick comes out clean. Let the cake cool completely in the pan.

  10. 10

    For the buttercream, beat the 250g room-temperature butter until pale and creamy. Ensure the pudding is the same temperature as the butter. Add the pudding to the butter one tablespoon at a time, whisking constantly until smooth and airy.

  11. 11

    Spread the buttercream evenly over the cooled cake. Chill in the refrigerator for at least 45 minutes to set the cream.

  12. 12

    Melt the dark chocolate and coconut oil together over a water bath (bain-marie). Let it cool slightly so it is pourable but not hot.

  13. 13

    Pour the chocolate glaze over the chilled buttercream layer, spreading it quickly with an offset spatula. While the chocolate is still soft, use a cake comb or a fork to draw wavy lines across the surface.

  14. 14

    Allow the chocolate to set at room temperature for a matte finish, or in the fridge for a snap. Slice into rectangles and serve.

💡 Chef's Tips

Temperature is key: Ensure the pudding and the butter for the cream are at the exact same room temperature to prevent curdling. Drain the cherries very well; excess moisture can make the cake soggy around the fruit. Use a hot, dry knife to slice the cake; this prevents the chocolate topping from cracking and keeps the layers clean. If the buttercream curdles, gently warm the bowl over a water bath for a few seconds and continue whisking. For the best flavor, make the cake a day in advance to let the layers meld together.

🍽️ Serving Suggestions

Serve with a generous dollop of unsweetened whipped cream on the side. Pairs perfectly with a strong German filter coffee or a dark roast espresso. For a festive touch, serve alongside a glass of chilled dessert wine or Riesling. Enjoy as a mid-afternoon treat, the traditional 'Kaffee und Kuchen' way.