Preheat and Prepare the Pan
Preheat the oven to 325°F (165°C).
Line an 8x8-inch metal baking pan with parchment paper, leaving some overhang for easy removal.
Make the Brownie Base
In a large mixing bowl, whisk together the egg, vegetable oil, and water until well combined.
Add the boxed brownie mix and stir until smooth and no streaks of mix remain.
Spread the brownie batter evenly into the prepared pan using a spatula.
Pre-Bake the Brownies
Bake the brownie base for 25 minutes, or until the top is set but the center is still slightly wiggly. Remove the pan from the oven, but keep the oven on.
Add the Hello Dolly Layers
Sprinkle the sweetened shredded coconut evenly over the partially baked brownies.
Follow with a layer of chopped pecans, then sprinkle the semi-sweet chocolate chips and butterscotch chips on top.
Drizzle the sweetened condensed milk evenly over the entire surface.
Finish Baking
Return the pan to the oven and bake for another 20 minutes.
The brownies are done when a toothpick inserted into the center comes out with a few crumbs, and the coconut is golden brown.
Cool and Slice
Let the brownies cool in the pan for at least 1 hour.
Use the parchment paper to lift the brownies out of the pan and slice into 24 rectangular pieces.