Step 1: Preheat your oven to 350°F (175°C) and grease a 9×13 inch baking pan or line it with parchment paper.
Step 2: In a large bowl, whisk together the melted butter and sugar. Add the eggs one at a time, followed by the vanilla extract.
Step 3: Sift in the cocoa powder, flour, and salt. Fold gently until just combined. Pour into the prepared pan and bake for 25 minutes. Let cool completely.
Step 4: Use a 3-inch round cookie cutter to cut 12 circles out of the cooled brownie slab to form the base of the wicked witch hat brownies.
Step 5: Melt the chocolate wafers in a microwave-safe bowl in 30-second increments until smooth. Dip each cone into the chocolate until fully coated. Place on wax paper to set.
Step 6: Once the cones are dry, pipe a thick ring of purple frosting around the open edge of the cone.
Step 7: Press the frosted cone onto the center of a brownie circle. Attach a yellow star sprinkle to the frosting ribbon to act as the buckle.