1. Preheat oven to 350°F or 325°F for dark or nonstick coated pans. Spray a 13x9x2-inch baking pan with non-stick spray; set aside.
2. In a medium bowl, sift together the flour, 1 1/4 cups sugar, cocoa powder, baking soda and salt; set aside.
3. In a large measuring cup, mix together the buttermilk, food coloring, white vinegar and vanilla. Stir lightly until mixed.
4. In a large mixer bowl with electric mixer on low speed, beat oil and eggs until well mixed. Add buttermilk mixture and beat until blended.
5. Reduce speed to low and gradually add flour mixture. Beat until blended. Pour mixture into prepared pan.
6. Bake until a toothpick inserted in center comes out clean, about 30 minutes. Immediately poke holes in the cake with handle of wooden spoon. Let cool.
7. For fillling/frosting, in mixer bowl on high speed, beat cream cheese and 1/3 cup sugar until smooth. Reduce speed to low and mix in whipped topping.
8. Spread mixture over cooled cake, filling in poked holes. Smooth remaining mixture over cake. Refrigerate until chilled.

Serves: 24