01 -
Preheat oven according to brownie mix package instructions, typically 175°C. Grease a 23x33 cm (9x13 inch) baking pan with butter or non-stick spray, or line with parchment paper leaving overhang for easy removal.
02 -
Combine brownie mix with specified eggs, vegetable oil, and water. Stir gently until smooth and just combined to avoid tough texture.
03 -
Pour batter evenly into prepared pan. Bake following package directions, generally 25-30 minutes, until a toothpick inserted near the center has moist crumbs. Avoid overbaking.
04 -
Allow brownies to cool completely in pan at room temperature for at least 60 minutes to prevent frosting from melting.
05 -
Transfer vanilla frosting to bowl. Add gel food coloring dropwise, stirring thoroughly until desired vibrant color is achieved.
06 -
Spread colored frosting evenly over cooled brownies using an offset spatula. Immediately apply Halloween sprinkles and randomly press candy eyes of various sizes into frosting for a playful appearance.
07 -
Let decorated brownies rest for 15-20 minutes to allow frosting to firm slightly. Slice into 12 equal squares with a clean, sharp knife cleaned between cuts for neat edges.