In large bowl, stir together cake mix, pudding (dry) and flour until blended. Reserve 1 tablespoon; set aside. Add sour cream, eggs, butter and vanilla; stir until thoroughly mixed. In small bowl, toss 1 tablespoon reserved dry mixture with baking chips until chips are well coated. Stir in baking chip mixture; batter will be very thick. Spread about 2 1/2 cups batter in each pan.