How to make upside-down plum cake

• Grease the leak-proof pan with a thick layer of butter and sprinkle with sugar.
  butter, 70 g sugar
  
• Halve the plums, remove the pits, and arrange them cut-side down, tightly covering the bottom.
  approx. 500-600 g plums
  
• Sift the flour, baking powder, and spices through a sieve.
  300 g wheat flour - all-purpose, 2 teaspoons baking powder, 1 teaspoon cinnamon, 1 teaspoon cardamom, 0.5 teaspoons ginger
  
• Beat the softened butter with sugar for several minutes until the mixture becomes voluminous and the butter turns pale.
  170 g butter, 150 g sugar
  
• Add one egg and one tablespoon of flour at a time to the butter mixture - mix briefly.
  2 eggs
  
• Add approximately half of the flour and the yogurt, and mix briefly until combined.
  250 ml natural yogurt
  
• Add the remaining flour and mix on low speed - turn off the mixer when there are still traces of flour visible on the edges.
• Gently fold the batter with a spoon.
  
• Spread the batter over the plums in an even layer.
  
• Bake at 170 degrees Celsius (fan-assisted oven) for about 35-40 minutes - until a skewer comes out clean.
• After baking, cool the cake on a wire rack for 10-15 minutes.
• With a sharp knife, loosen the cake around the edges of the pan, then place a larger plate on top of the cake.
  
• Carefully invert the cake and remove the pan.
  
• You can serve the cake warm with ice cream, or after it has cooled.