Additional items needed: parchment paper and two 9-inch cake pans
Preheat and prepare the pan.
Preheat the oven to 325 degrees. Cut circles of parchment to fit in the bottom of the cake pans. Lightly spray the bottom and sides of the cake pans, add the parchment, then lightly spray the parchment. Using the parchment is essential in getting the brownies out of the cake pans in one piece.
Make the brownie batter.
In a large bowl combine the brownie mix, eggs, water, and cooking oil. Whisk well to incorporate. Divide the batter between the prepared cake pans and smooth into an even layer.
Bake the brownies for 25-35 minutes or until a toothpick inserted in the center of comes out clean. Tent with foil for the last 10 minutes if browning too quickly. Remove from the oven and cool for 10 minutes on a wire rack. Gently loosen the baked brownie from the pan, invert onto the wire rack, peel back the parchment paper, and discard. Cool brownie completely.
Melt the chocolate.
Combine the chocolate chips and 1/4 c heavy cream and microwave for 1 minute then stir. Continue to heat chocolate mixture for 15 seconds at a time until chocolate is completely melted and smooth. Spoon onto the inverted (smoother side), cooled brownie and spread chocolate layer evenly with a butter knife or offset spatula. Let cool.
Make the white icing.
Combine the powdered sugar and remaining 1/4 c heavy cream in a small bowl. Mixture will be thick, not fluid. Add 1-2 tsp additional cream if icing seems too dry. Spoon icing into a zip top bag and squeeze the mixture into one corner to make a pastry bag.
Decorate the brownie.
Snip off a small corner of the zip top bag and pipe a spiral pattern beginning in the center of the chocolate covered brownie and work toward the edge. Gently drag a toothpick through the white icing and chocolate to create a spiderweb design.
Adapted from BuzzFeed