Make the Brownies:

1. Preheat the oven to 350°F (175°C). Grease a 9×13-inch pan with non-stick spray.
2. In a large mixing bowl, whisk together cocoa powder and oil until combined.
3. Add softened butter and mix until smooth.
4. Stir in granulated sugar and mix for 1 minute.
5. Add eggs one at a time, mixing after each addition. Stir in vanilla extract.
6. Gradually add flour and salt, mixing just until combined.
7. Pour the batter into the prepared baking pan, spreading it evenly.
8. Bake for 30-40 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs.
9. Let the brownies cool completely before adding frosting.

Make the German Chocolate Frosting:

1. In a medium saucepan, combine brown sugar, granulated sugar, butter, egg yolks, and evaporated milk over medium heat.
2. Stir constantly for about 5 minutes, until the mixture thickens.
3. Remove from heat and stir in vanilla extract, chopped pecans, and shredded coconut.
4. Let the frosting cool completely before spreading over the brownies.

Assemble the Brownies:

1. Once the brownies have fully cooled, evenly spread the German chocolate frosting over the top.
2. Slice into squares and enjoy!