Preheat an oven to 180c (350f) and prep a parchment paper-lined 8 by 8 brownie pan.
Into a large mixing bowl, add the melted and cooled butter, and add the granulated sugar, vanilla extract, vinegar, and kosher salt. Mix with a whisk until well combined.
Add the eggs and egg yolk and mix with a whisk for 4-5 minutes until some of the sugar is melted. This will create the crackly top of the brownies.
Sift the cocoa powder and mix until well combined and smooth.
Add the gel red food coloring to the batter and mix until well combined.
Add the flour and mix until just combined and there are no lumps of flour showing. Do not overmix to keep the brownies fudgy on the inside.
Pour the brownie batter onto a parchment paper lined 8 by 8 brownie pan and smooth it out with a spatula. Bake in a 180c (350f) preheated oven for 30-35 minutes. Do not overbake them to keep it fudgy!
Allow the brownies to cool for about 1 hour before slicing, so they won't crumble and fall apart.
Make the cream cheese glaze
In a small mixing bowl, mix cream cheese, powdered sugar, vanilla extract, and kosher salt, and drizzle the brownies with as much glaze as you like. Top with Valentine’s Day sprinkles if desired and enjoy!
Notes
Use room temperature ingredients. It is important that you use room-temperature ingredients like eggs. This step ensures that your mixture mixes into a homogenous mixture and bakes perfectly. you don’t want to place cold batter into the oven.
Use gel red food coloring for these brownies. You will only need a few drops instead of using the whole bottle to reach the vibrant color.
Don’t overmix the batter, you don’t want to develop the gluten in the flour. This step ensures you have moist brownies and not dense and dry brownies.
Measure your flour correctly! When measuring your flour, avoid scooping it with a measuring cup. Instead, stir the flour with a spoon to create as many air pockets as possible, and spoon it into your measuring cup. Finally, level it with a back of a knife.
Be patient! I know it’s extremely tempting to eat these brownies as they are pulled out of the oven, but allow these brownies cool for at least 20 minutes so they will be more firm and won’t crumble up.
Don’t overbake your brownies! to have super moist brownies, we like to underbake the brownies a little bit. The brownies continue to bake a little bit more in the cooling process.
Ensure you line your baking pan with parchment paper to prevent the brownies from sticking to the pan.