01 -
Line a 9x9 inch metal baking pan with parchment paper, making sure there is an overhang for easy removal.
02 -
In a large bowl, whisk together melted butter and granulated sugar until smooth. Add eggs one at a time and whisk until glossy and thick, then blend in vanilla extract.
03 -
Sift together all-purpose flour, unsweetened cocoa powder, and kosher salt. Fold the dry mixture into the wet ingredients just until combined.
04 -
Gently fold in semisweet chocolate chips and coarsely crushed Oreo cookies until distributed throughout the batter.
05 -
Pour the brownie batter into the prepared pan and spread evenly with a spatula to ensure a uniform surface.
06 -
Arrange whole and broken Halloween Boo Oreo cookies decoratively over the surface, ensuring festive designs face upward.
07 -
Bake at 350°F (175°C) for about 30 minutes, or until the top is shiny, slightly cracked, and the edges are set. Avoid overbaking.
08 -
Allow brownies to cool completely in the pan for approximately 2 hours to establish a firm, sliceable texture.
09 -
Use a large chef’s knife to cut brownies into even bars by pressing down in one motion. Wipe the blade between each slice for sharp, clean edges.