The first main difference is that these triple chocolate brownies are made using both chocolate and cocoa powder while the cocoa powder brownies are made entirely with cocoa powder (without any chocolate). The cocoa powder brownies are also darker in color and more dense and soft in texture. The chocolate brownies, on the other hand, are definitely of a lighter shade and despite being deliciously moist on the inside, are not as dense as compared to the fudgy cocoa powder brownies. This is because the proportion of flour and cocoa powder to butter is much more in the cocoa powder brownies than in these chewy chocolate brownies which explains its lighter texture.  The fudgy cocoa powder brownies are made entirely with brown sugar, hence the deep dense and fudgy texture of the brownies while these chewy brownies are made entirely with white sugar. White sugar mixed into hot melted butter produces the crinkled top that gives the triple chocolate brownies a lovely light crunch on the top and a light and moist texture on the inside. My cocoa powder brownies do not produce such a crinkled top, rather it has a shiny smooth top.