How to make rhubarb square cake step by step

Step 1 - preparations

• Take out the cake ingredients from the fridge in advance - especially butter and eggs, so they warm up to room temperature.
  225 g butter, 2 eggs
• Line the baking pan with baking paper or grease it with butter and dust with flour.
  
• Wash the rhubarb and cut off the ends from both sides. Cut the rest of the stalk into pieces about 1.5 cm wide.
  approx 1 kg rhubarb
• Transfer the rhubarb to a bowl and add the remaining ingredients - mix thoroughly.
  2 tablespoons potato starch, 80 g sugar
  
• Turn on the oven to top-bottom heating at 180℃ or convection at 170℃.

Step 2 - preparing the creamed cake dough

• Mix together the flour and baking powder.
  450 g wheat flour - all-purpose, 2 teaspoons baking powder
• Transfer butter and sugar to a large bowl - start beating with a mixer on high speed.
  225 g butter, 150 g powdered sugar
  
• Beat for about 3 minutes - until the mixture becomes light and visibly fluffy.
  
• Reduce mixer speed and add one egg at a time and a little flour - mix briefly on low speed - just until combined.
  2 eggs
  
• Add the remaining flour in portions and mix briefly.
  
• Stop mixing when there are still remnants of flour visible - then just mix in the dough with a spoon - the dough will be thick!
  

Step 3 - layering the cake

• Spread about half of the dough evenly on the bottom of the prepared pan.
  
• Spread the rhubarb filling over the dough.
  
• Spoon portions of the remaining dough over the rhubarb, then gently spread it out.
  

Step 4 - baking the cake

• Place the pan with the cake into the preheated oven and bake for about 40-45 minutes - until a wooden skewer comes out clean.
• After baking, cool the cake, and before serving, sprinkle with powdered sugar or drizzle with glaze.