Halloween Brownies

Directions

1. Preheat oven to 325°F. Butter a 9-by-13-inch baking pan. Line bottom and long sides with parchment, leaving a 2-inch overhang. Butter and flour parchment, tapping out excess; set aside.
2. Whisk together flour and salt. In a large heatproof bowl set over (not in) a pot of simmering water, melt butter. Remove from heat. Add both sugars; whisk to combine. Whisk in cocoa powder.
3. Add eggs, one at a time, and whisk until well combined and glossy. Mix in vanilla. Add flour mixture; stir until just combined (do not overmix).
4. Pour batter into prepared pan; smooth top with a spatula. Bake until top is crackly and a tester inserted into center comes out clean, about 30 minutes.
5. Transfer pan to a wire rack. Let cool 30 minutes, then lift brownies out of pan using parchment overhang. Let cool completely on wire rack, then cut into 24 pieces (for spider webs, cut into squares; for mummies, cut into rectangles.)
6. While brownies are cooling, beat confectioners' sugar, meringue powder, and water with a mixer on low speed until fluffy but dense, 7 to 8 minutes.
7. Transfer icing to a piping bag fitted with a small round tip (such as Ateco #3). Pipe long lines in corners of square brownies, then connect with icing to create a web shape.
8. Transfer icing to a piping bag fitted with a small ribbon tip (such as Ateco #44.) Pipe ribbons of icing back and forth to create a mummy pattern, and decorate with candy eyeballs.