Preheat your oven to 350°F (175°C). Grease an 8x8-inch baking pan with butter and line with parchment paper.

In a mixing bowl, whisk together the melted butter and granulated sugar until combined. Add the eggs, one at a time, stirring well.

Mix in red food coloring, vanilla extract, and salt until glossy.

Sift together flour and cocoa in a separate bowl, then fold into the wet mixture gently.

In another bowl, beat the cream cheese until smooth. Add the additional egg and sugar, mixing until fluffy.

Pour half of the brownie batter into the pan and dollop half of the cream cheese mixture on top. Swirl together.

Repeat with the remaining brownie and cream cheese mixtures, swirling for a marbled effect.

Bake for 35-40 minutes until a toothpick comes out with moist crumbs. Cool completely before slicing.