Preheat the oven to 350°F (180°C), or 160°C if using a fan oven. Line a 9x9 inch (22x22 cm) baking pan with parchment paper and set aside

In a medium bowl, whisk together the flour, cocoa powder, and salt; set aside.

In a separate bowl, whisk together the melted butter, sugar, and brown sugar until smooth. Add the eggs, vanilla, and apple cider vinegar and whisk until fully combined.

Stir in the melted chocolate and red food coloring until desired shade of red is reached.

Gently stir in the flour mixture until just combined and no dry streaks remain.

Transfer mixture into the prepared pan and bake for 30-35 minutes or until a toothpick inserted in the center of the pan comes out clean or with a few moist crumb.

Allow the brownies to cool completely.

Meanwhile, prepare the frosting by creaming together the butter and cream cheese.

Add the powdered sugar in 2-3 smaller additions and the vanilla extract, mixing well after each sugar addition.

Spread the cooled brownies with a generous layer of cream cheese frosting, then sprinkle with shaved white chocolate.