Preheat your oven to 350°F (175°C). Grease a 9x13-inch baking pan or line it with parchment paper.
In a medium saucepan, melt the butter over low heat. Remove from heat and let cool slightly.
In a large bowl, whisk together cocoa powder, granulated sugar, brown sugar, and flour until combined.
Pour the melted butter into the dry ingredients along with the eggs and vanilla extract. Stir until just mixed; do not overmix.
Spread the brownie batter evenly in the prepared pan and bake for 20-25 minutes, or until a toothpick inserted comes out mostly clean.
While baking, mix sweetened condensed milk, coconut flakes, and chopped pecans in a separate bowl.
Once brownies are done, remove from oven and spread the topping mixture over them evenly.
Return to the oven for an additional 10-15 minutes until golden brown on top. Allow cooling before slicing.
