Place the butter, both sugars, chocolate, and molasses in a saucepan. Cook over low heat, stirring, until the butter and chocolate are melted. Do not melt the sugar granules. Allow the mixture to cool. Room temperature is good, but lukewarm will do as well.
Meanwhile, beat the eggs and vanilla extract until fluffy. Add chocolate mixture and beat on low speed until just combined.
Add flour, cocoa powder and baking powder. Again, mix on low speed until ingredients are incorporated. Mixing for a long time or on high speed is not necessary or your brownies will not be as creamy as you want them to be.
Pour the batter into a 20×20 cm/8x8 inch baking pan lined with parchment paper and spread evenly.
Bake the brownie at 190°C/375℉ (conventional) for 25 minutes.
The top should look dry after baking, but the inside should still be soft and creamy.
Let the brownie cool completely in the baking pan before taking it out and cutting it into pieces.
Tips
To cool the mixture in the pan faster, you can place the pan in a bowl of cold water. The pan will cool down immediately, so the mixture will also cool down faster.
How to store
Approximately 4-5 days shelf life when properly packaged.