Preheat the oven to 325. Line a 9 x 13 baking dish with parchment or foil, then spray with cooking spray and set aside.
In a large bowl, mix together the butter, sugar, eggs, and vanilla. Add the cake flour, cocoa powder, baking soda, and salt, and mix until combined. Add the chocolate chunks, and mix to combine.
Spread the mixture in the prepared pan. Bake 20 minutes, then remove from the oven.
Sprinkle the chocolate chips and shredded coconut over the top of the brownies, then pour the sweetened condensed milk over the top, covering evenly. Return to the oven and bake 25-30 minutes, or until the coconut is golden brown and the brownies no longer jiggle when slightly shaken.
Remove from oven and sprinkle with additional chocolate chips, if desired. Allow to cool completely before serving.