Preheat the oven to 350 degrees F. Line a 9x13-inch baking dish with parchment paper and spray with non-stick cooking spray, set aside.
In a large pot or dutch oven, place the cut butter and begin to melt the butter over medium-low heat.
Add the german chocolate squares to the pot, occasionally stirring, and melt the chocolate with the butter until smooth.
Take the pot off the heat and whisk in the sugar until combined and smooth.
Next, add in the eggs one at a time and whisk each of them in fully before adding the next one.
Whisk in the vanilla and salt.
Add the flour and stir it in until fully combined and there are no remaining dry patches.
Pour into the prepared baking dish.
Place in the oven and bake for 35-38 minutes until a toothpick inserted into the center comes out mostly clean.
Remove from the oven and Place on a wire rack to cool completely.
Once the brownies are cool, make the topping. In a medium-sized saucepan, add the sugar, evaporated milk, butter, and egg yolks.
Place the saucepan over medium-low heat and stir everything together. Then, stir occasionally until the butter has melted.
Bring the mixture to a simmer while still stirring often so nothing sticks to the bottom. Once it hits a simmer and thickens slightly remove from the heat, this will take roughly about 12 minutes.
Add the coconut, pecans, and vanilla and stir to combine. Continue to stir until thickened and spreadable, about 5 minutes.
Pour the frosting on top of the brownies and with an offset spatula, smooth it out. Then let the topping cool completely.
Cut into bars and drizzle with melted chocolate if desired and serve.