When I lived in Vienna I occasionally treated myself to a Marzipankartoffel from the traditional Viennese pastry store Konditorei K.u.K. Hofzuckerbäcker L. Heiner. The Marzipankartoffel, marzipan potato, is a little pastry that is filled with a whipped ganache, sandwiched between two sponge cakes and coated with a thin layer of marzipan that is rolled in cacao powder.
Visiting the Heiner pastry store and buying a Marzipankartoffel, which was always wrapped in a transparent paper bag that was sealed with a dark red logo sticker of the pastry store ( I kept one of those bags with the sticker as a memory), was always a joyful moment and I often think about these visits and I often long for one of those delicate and indulgent little cakes.



It took me quite a while to recreate the Marzipankartoffeln of the Heiner pastry store but after a few trials and errors I created a recipe that taste as the cakes from the Heiner pastry store (or as I remember how they tasted). It is always an incredible feeling creating a recipe that one was working for a while and it makes me so happy to share the recipe with you, dear readers.
It takes a little bit of time to make these Marzipankartoffeln but, maybe it is just me, it is a very soothing activity and at the end you can eat these delicious little cakes.


Makes 10 - 15 marzipan potatoes

Sponge Cake

  • 85 g egg whites (equals 2 1/2 eggs)
  • 1 pinch of salt.
  • 40 g egg yolks (equals 2 eggs)
  • 35 g / 2 1/2 tablespoons granulated sugar
  • 1 teaspoon warm water
  • 35 g /  1/4 cup all-purpose flour
  • 15 g / 2 tablespoons potato starch
  • 1 tablespoon vanilla sugar
  • Preheat the oven to 190 °C / 375 °F.
  • Prepare 1-2 baking sheets with parchment paper. Draw 30 circles (I use a cookie cutter) that are 4 cm / 1,5 inches or 5 cm / 2 inches wide in diameter (I prefer  the smaller size). Make sure that there is some space between each circle. Turn your baking sheet over, so that your pencil does not come off in your sponge cakes.
  • Beat egg whites with a pinch of salt until almost stiff, gradually add sugar and whisk until stiff.
  • Mix egg yolks, vanilla sugar and 1 teaspoon of warm water.
  • Fold the egg yolk mixture into the beaten egg whites.
  • Sift the flour and potato starch over the egg mixture, gently fold in the flour.
  • Fill the batter into a piping bag and pipe the batter onto the circles that you draw on the baking paper.
  • Bake the sponge cakes for 10 to 12 minutes or until they are golden in color. Let the cakes cool for a few minutes, carefully remove the cakes from the baking sheet (I use a knife) and let the cakes cool completely on a wire rack.

Whipped ganache

  • 150 g / 2/3 cup heavy cream
  • 150 g / 5.3 oz chocolate (50%), chopped finely
  • Heat the heavy cream in a small saucepan until it has reached 80 °C / 175 °F. Set aside and add the finely chopped chocolate. Stir until the chocolate is completely melted.  Pour the mixture into a bowl, cover with plastic wrap and place the bowl in the fridge. As soon as the whipped ganache is almost thick - which takes about 30 - 45 minutes, the ganache should not be firm, it is more a pudding-like consistency - whip the ganache for about a minute with an electric mixer. You will notice that the texture gets lighter in color. Be carefully that you do not over-whip the ganache. Use the whipped chocolate immediately because it will firm up over time.

Coating

  • 50 g / 9 oz marzipan
  • Cofectioners' sugar
  • 1 tablespoon unsweetened raw cacao
  • Sprinkle your work surface with confectioners' sugar and roll out the marzipan until it is 1 mm thick. If you like a thicker marzipan coat, feel free to do so but you might need a little more marzipan. Cut out circles which are about 8 cm / 3 inches wide or 10 cm / 4 inches (for the bigger cakes) in diameter.

Assembling

  • Spoon the chocolate whipped cream on each sponge cake shell (about one teaspoon for the small and 1 1/2 for the bigger cakes) and sandwich them together.
  • Carefully cover the sandwiched cookies with the rolled out marzipan. Trim off excess marzipan with a sharp knife.
  • Sift cacao powder onto a plate. Roll each marzipan potato in cacao powder and gently dust off any excess cacao.
  • Store the cakes in a cool place but room-temperature is fine (maybe not in the summer time), too. I keep my cakes on my kitchen table. I do not recommend storing the cakes in the fridge because I found that the cakes got a tiny bit soggy.
  • The Marzipankartoffeln will keep up to 5 days.