Beat together the butter, granulated sugar, and brown sugar until light and creamy.
Add the egg, vinegar, red food color, and vanilla, and mix until combined.
Sift in the flour, cocoa powder, baking soda, baking powder, and salt, and gently fold until just combined.
Refrigerate the dough for 15-20 minutes to firm up.
Preheat your oven to 375°F and line a cookie sheet with parchment paper.
Divide the dough into balls and flatten them slightly on the cookie sheet.
Bake for 10-11 minutes, then let cool.
Meanwhile, make the cream cheese frosting by whisking together the butter, cream cheese, icing sugar, and vanilla until creamy.
Pipe the frosting onto the cooled cookies and sprinkle with red velvet crumbs.