- Sieve the flour, cocoa powder and the baking powder together and keep aside. 
- Preheat oven to 350° F before baking. 
- Take eggs in a large bowl and beat well till frothy. Take an electric mixer/ hand blender/ egg whisk whichever is available and comfortable for you. Keep the speed of the blender at medium and beat well scraping down the sides occasionally. Beating the eggs well is a crucial step in the cake preparation. Beat for about 5 – 7 min. 
- Now add the powdered sugar slowly to the above mixture spoon by spoon while beating continuously till a creamy froth is formed. This will take about 5 min. 
- Now turn the electric mixer’s speed to low, add the flour mixture slowly while beating to avoid lumps. Add a spoonful at a time. Beat for 5 min more. 
- Add butter/ vegetable oil slowly. Keep beating while scraping down for some time intermittently. Beat well at least for 5 – 10 min until the mixture turns fluffy with frothy. 
- Grease the cake pan with butter or vegetable oil. Transfer the cake batter to the pan. Gently tap the pan to let some trapped air to come out. 
- Place the cake pan in the oven and bake for 45 min. 
- A simple test to check whether the cake is baked completely or not is to insert a toothpick in the centre. The toothpick should come out clean without any batter sticking to it. 
- If the toothpick comes out with the batter sticking to it, you have it bake the cake for some more time probably 5 – 10 min more. Generally, this cake is done within 45 min. 
- Take the cake out of the oven and set it aside to cool. 
- Take a knife and run it between the edges of the pan and the cake slowly. 
- Now take a plate on which you want to unmould the cake. Invert it on the top of the pan. 
- Turn the pan over with the plate on the platform. Slowly lift the pan and keep aside. 
- Cut the cake into the desired shape and serve.