Preheat your oven to 350°F (175°C). Line an 8x8-inch square baking pan with parchment paper, leaving an overhang on the sides for easy removal.
In a large mixing bowl, whisk together the melted salted butter and granulated sugar until the mixture is well combined and grainy.
Add the eggs and alcohol-free vanilla flavor. Whisk vigorously by hand for about 1 to 2 minutes until the batter looks smooth and shiny; this helps create a crackly top.
Sift in the Dutch-processed cocoa powder and all-purpose flour to ensure there are no lumps. Use a rubber spatula to fold the dry ingredients into the wet mixture until just combined.
Gently fold in the semi-sweet chocolate chips.
Pour the batter into the prepared baking pan and spread it evenly into the corners using a spatula.
Bake for 22 to 26 minutes. Test for doneness by inserting a toothpick into the center; it should come out with a few moist, fudgy crumbs attached, but not raw batter.
Remove the pan from the oven. While the brownies are still hot, randomly press the candy eyeballs into the surface to create a 'spooky' look. Scatter the orange and purple sprinkles over the top so they adhere to the warm chocolate.
Allow the brownies to cool completely in the pan for at least 1 hour. This is critical for achieving a fudgy texture and clean cuts.
Lift the brownies out of the pan using the parchment edges. Using a sharp knife dipped in hot water and wiped dry, cut the brownies into 9 large squares, cleaning the blade between each cut for a professional finish.