1. Prep the Pan Like a Pro
I start by preheating the oven to 350°F (176°C). Then, I spray a 9×9-inch square baking pan with non-stick spray and line it with parchment paper. Here’s my trick: I let the parchment hang over the sides by about 2 inches so it’s easy to lift the brownies out later. I even crisscross another sheet for extra insurance no stuck edges!

2. Make the Red Velvet Brownie Batter
In a big bowl, I whisk the melted butter and sugar until they’re totally combined. Next, I add the eggs, egg yolk, and vanilla, mixing until smooth. Then comes the fun part the red food coloring! I stir it in until the batter looks like a deep red velvet cake.

In a separate bowl, I whisk the flour, cocoa powder, cornstarch, and salt. I slowly add this to the wet ingredients, mixing just until everything’s combined. No overmixing we want fudgy, not tough!

3. Bake the Brownies
I pour the batter into the prepared pan, spread it evenly, and bake for 25–30 minutes. To test doneness, I poke a toothpick into the center. If it comes out with a few moist crumbs (not wet batter), they’re done! Let them cool completely in the pan. Patience is key here if the brownies are warm, the fudge layer will melt.

4. Whip Up the Oreo Fudge
For the fudge, I melt the condensed milk, white chocolate chips, and vanilla in a heatproof bowl over simmering water. Stirring constantly keeps it smooth. Once melted, I fold in the chopped Oreos and spread this over the cooled brownies. I press plastic wrap directly onto the fudge to flatten it evenly, then refrigerate for at least 4 hours .

5. Add the Chocolate Ganache Topping
The grand finale! I microwave the dark chocolate chips and heavy cream in 30-second bursts, stirring until silky. Then, I pour this ganache over the chilled fudge layer, spread it smoothly, and refrigerate again for 1 hour to set.

6. Slice and Serve!
Using the parchment “handles,” I lift the whole slab out of the pan and cut it into squares. A hot knife wiped clean between cuts gives you sharp edges.