1. Preheat oven to 350 degree F.
2. In a bowl sieve the flour, unsweetened cocoa powder, baking powder, baking soda and a pinch of salt. Mix with a fork, and the dry ingredients are ready
3. To prepare the wet ingredients, in a bowl add the butter, the can of condensed milk and sugar. Also add vanilla extract. Whip all these together till smooth.
4. Add the sour cream and blend again.
5. Gradually blend in the prepared dry ingredients to the wet ingredients small portions at a time.
6. Add coffee half portion at a time, blend and then add the remaining half. (Adding coffee is optional, water can be added instead). Add water as needed in the batter to adjust consistency of batter so if desired only 1/4th cup of hot water can be used to dissolve coffee and the rest regular hot water can be added later as needed.
7. Grease a baking tray and pour the batter into it. Bake in the preheated oven for 25 to 30 minutes. Check if the brownie is done when a toothpick inserted comes out clean. Remove from oven and allow brownie to rest in pan for 10 minutes.
8. The delicious chocolate brownies can be served topped with pecans and fresh strawberries or with a scoop of vanilla ice cream or dusted with powdered sugar.