• Line a 9 x 13" cake pan with parchment paper. Leave an overhang to make removing the brownies from the pan easier.
• Arrange your oven rack to the center position. Preheat your oven to 350°F.

Make the Brownies:

• Add 1 cup of unsalted butter to a large, microwave-safe bowl. Microwave in 15-30 second intervals until about halfway melted. Add 1 cup of semi-sweet, dark, or milk chocolate, and continue to microwave in 15-30 second intervals, whisking between, until melted and smooth.
• Whisk in the granulated and brown sugar until well combined. Add the room temperature eggs and vanilla extract and whisk until smooth.
• Add the flour, sifted cocoa powder, and salt, and mix until the batter is completely smooth. Mix in the red gel coloring until you're happy with the color.
• Fold in the 1 cup of white chocolate and spread the batter out evenly in the lined cake pan.
• Bake the brownies in the preheated oven for 16-20 minutes, until a toothpick inserted in the center comes out with a few moist crumbs attached.
• Let the brownies cool in the pan and then cool completely in the fridge before adding the cream cheese frosting.

Make the Cream Cheese Frosting:

• In a large bowl, use an electric mixer to beat the softened butter and cream cheese until smooth without any lumps. Add the powdered sugar, cream (or milk), and vanilla extract, and mix until the frosting is smooth.
• Once the brownies have cooled, use an offset spatula to spread the cream cheese frosting over the top. Add sprinkles, if desired, and cut into even-size bars.