01 -
Preheat oven to 177°C and line an 20x20 cm square baking pan with parchment paper, leaving overhang for easy removal.
02 -
Melt the butter in a small saucepan or microwave until fully liquefied, then transfer to a medium mixing bowl.
03 -
Add granulated sugar and light brown sugar to melted butter and whisk until mixture forms a paste that pulls away from the bowl sides.
04 -
Incorporate the egg, white vinegar, vanilla extract, and red food coloring. Adjust red food coloring quantity to achieve desired intensity and mix until uniform.
05 -
Sift together cocoa powder, salt, and all-purpose flour, then gently whisk them into the wet mixture just until combined—avoid overmixing.
06 -
Pour batter into the prepared pan and bake for 30 to 40 minutes. Test doneness by inserting a toothpick in the center; it should come out with moist crumbs but no wet batter. The top should appear crinkled.
07 -
Remove from oven and allow to cool completely in the pan while preparing the frosting.
08 -
Using a handheld or stand mixer, beat cream cheese and butter together with salt and vanilla extract until smooth. Gradually add powdered sugar until desired consistency is achieved. Add cornstarch if using dairy-free cream cheese to thicken.
09 -
Refrigerate frosting until brownies are fully cooled and ready to be frosted.
10 -
Spread the cream cheese frosting evenly over cooled brownies, then slice and serve.