25 g unsweetened Cocoa powder
3 Tablespoons Boiling Water
3 large Eggs, room temperature
1 1/2 Teaspoons Vanilla extract
125 g sifted all-purpose flour
1 Teaspoon Baking powder
1/4 Teaspoon Salt
175 g granulated white sugar
185 g unsalted Butter / Margarine
1. In a bowl mix the cocoa powder into the boiling water until smooth.
2. Let coca mixture cool at room temperature and then whisk in the eggs and vanilla extract.
3. Combine the dry ingredients i.e. flour, baking powder, salt, and sugar and mix on low speed until blended.
4. Add the butter and half of the chocolate/egg mixture. Mix on low speed until the dry ingredients are moistened and smooth mixture is obtained.
5. Gradually add the remaining egg mixture and beat well after every installment.
6. Put in pre-heated oven for 10-20 minutes (depending upon oven) at 175 C.
7. Check regularly by inserting toothpick or knife in center, if material come with it, then it needs more time.
Source of Recipe