Preheat your oven to 350 degrees, and heavily spray a 9 by 13 inch pan with cooking spray.
In a large bowl, whisk together the flour, sugar, cocoa powder, baking powder, and salt. Add in one egg, 1 stick of the melted butter, the buttermilk, and the red food coloring. Mix until thoroughly combined. The dough will be thick (I used my hands to fully combine). Press it into the bottom of the pan.
Beat the cream cheese until fully smooth, about two minutes, scrapping down as needed. Beat in the 2 remaining eggs, the other stick of melted butter, and the vanilla. Beat in the powdered sugar one cup at a time until creamy. Pour over the bottom layer.
Bake for 35 to 40 minutes until the edges are golden brown and the center is still a little gooey. Cool completely, dust with powdered sugar, and cut.