Preheat oven to 325° F. Grease a 9 x 13-inch pan; set aside.
In a large saucepan, melt butter over medium heat. Add cocoa, white granulated Pioneer Sugar, and Pioneer Golden Light Brown Sugar; stir until well blended.
Turn off heat and add eggs one at a time along with the oil and vanilla; mix well. Add flour and baking soda stir until smooth. Make a dent in batter and pour in the vinegar. Mix well.
Pour into prepared pan and bake for 22 minutes. Test with knife to see if it comes out clean, if not continue cooking for few more minutes until done. Remove from the oven and set on wire rack to cool.
These brownies also taste excellent with frosting.
Pioneer Sugar is the brand of Michigan Sugar Company, a cooperative owned by nearly 900 farmers from Michigan and Ontario, Canada. The company has been extracting pure, all-natural sugar from sugarbeets since 1906. We are proud of our past and excited about our future. Learn more about our company at www.michigansugar.com.