Preparing the Cookies:

1. Preheat the oven to 350°F (175°C). Line two baking sheets with parchment paper.
2. In a medium bowl, whisk together flour, cocoa powder, baking soda, and salt. Set aside.
3. In a large bowl, beat softened butter, granulated sugar, and brown sugar until light and fluffy (about 2 minutes).
4. Add the egg, vanilla extract, food coloring, and vinegar to the butter mixture. Beat until fully combined.
5. Gradually mix the dry ingredients into the wet ingredients, alternating with buttermilk. Stir just until combined.
6. Use a cookie scoop or tablespoon to form dough balls and place them 2 inches apart on the prepared baking sheets.
7. Bake for 10–12 minutes or until the edges are set and the centers look slightly underbaked. Cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.

Making the Frosting:

1. Beat cream cheese and butter in a medium bowl until smooth and creamy.
2. Gradually add powdered sugar, one cup at a time, mixing until fully incorporated.
3. Stir in vanilla extract for added flavor.

Frosting the Cookies:

1. Once the cookies are completely cool, spread or pipe cream cheese frosting on top.
2. Decorate with sprinkles or a drizzle of melted chocolate, if desired.