Pre-heat oven to 350 degrees. Line a 9 inch square baking pan with non-stick foil or parchment paper. In a microwave safe mixing bowl, add butter, oil, and cocoa powder. Microwave until butter is melted. add sugar, eggs, and vanilla. Add in red coloring and vinegar. Mix until well incorporated. Add flour and salt. Pour into lined pan and bake for 30 minutes. Cool on a wire rack and cut into squares.
