Preheat oven to 350°F. Line an 8x8 square pan with foil and spray thoroughly with cooking spray. Set aside.

Line bottom of pan with Oreo cookies.

In a large bowl, prepare brownie mix as specified on box (as for fudgy brownies), and pour brownie mix over the cookies. Spread evenly to edges.

Break cookie dough into clumps and press into the brownie mix.

Bake brownies for roughly 30 minutes or until a toothpick inserted in the center comes out with fudgy crumbs but no raw dough. Let brownies cool completely.

In the bowl of a mixer, beat butter, cream, and vanilla on medium-low until smooth and well-combined. Slowly add powdered sugar.

Once powdered sugar is barely mixed in, increase speed to medium-high and beat for 2 minutes. Fold in crushed Oreos. Add blue food coloring until you achieve your desired shade of blue.

Frost cooled brownies.

In a microwave safe bowl, heat chocolate chips and heavy cream, stopping to stir every 20 seconds until smooth.

Stir in light corn syrup and let sit until thickened and cooled.

Drizzle ganache over cooled brownies and press mini cookies into the top to garnish.