Preheat and prep: Set your oven to 350°F (175°C). Line a 9x13-inch pan with parchment, leaving overhang on two sides for easy lifting. Lightly grease the parchment.

Melt the butter: In a microwave-safe bowl, melt butter until smooth. While warm, whisk in granulated and brown sugars until glossy.

Whisk in eggs and vanilla: Add eggs one at a time, whisking well after each. Stir in vanilla. The mixture should look thick and shiny.

Combine dry ingredients: In a separate bowl, whisk flour, cocoa, baking powder, and salt. Fold dry ingredients into the wet mix just until combined. If using chocolate chips, fold them in now. Don’t overmix.

Bake: Spread batter evenly in the pan. Bake 22–28 minutes, until a toothpick comes out with moist crumbs, not wet batter. Err on the side of slightly underbaked for fudgy brownies.

Cool completely: Let the brownies cool in the pan on a rack. This helps them set for clean cuts and neat decorating.

Add chocolate top layer: Melt semisweet/dark chocolate chips with 1 tablespoon oil in 20–30 second bursts, stirring between each, until smooth. Spread over cooled brownies with an offset spatula. Let set 10–15 minutes until no longer runny.

Create the “bandages”: Melt white chocolate or candy melts the same way. Transfer to a piping bag or a zip-top bag with a tiny corner snipped off. Drizzle back and forth in thin, crisscross lines to mimic mummy wrappings. Keep lines irregular—that’s what makes them look realistic.

Place the eyes: While the white drizzle is still soft, press two candy eyes near the top area of each future square. If it sets too fast, add a tiny dot of melted white chocolate as glue.

Set and slice: Chill for 10–15 minutes to firm up. Lift the slab out using parchment. Warm a sharp knife under hot water, dry it, and cut into neat squares or rectangles. Wipe the knife between cuts.