Preheat your oven to 350°F (175°C). In a large mixing bowl, combine the box brownie mix, oil, and ingredients specified on the package. Stir until blended and smooth. Pour the brownie batter into a greased baking pan.

Place the pan in your preheated oven and bake for 20-25 minutes. Check for doneness with a toothpick; it should come out with a few moist crumbs. Let the brownies cool completely in the pan.

Spread a layer of chocolate frosting over the cooled brownies using an offset spatula, ensuring an even coat.

Sprinkle crushed Oreos over the frosted brownies to create the 'dirt' effect, pressing the crumbs gently into the frosting.

Mix green food coloring into the leftover frosting and pipe it in swirling vine shapes across the brownies.

Arrange pumpkin candies on top, pressing them gently into the icing.