Heat oven to 350°F. Lightly grease 10-inch Bundt cake pan.
Cut chocolate pouch open at top corner. Squeeze half of chocolate batter into prepared pan.
Cut vanilla pouch open at top corner. Squeeze all of vanilla batter on top of chocolate batter.
Squeeze remaining chocolate batter on top of vanilla batter.
Using a knife or spatula, gently swirl batters together.
Bake for 40-45 minutes or until a toothpick inserted into the center comes out clean.
Cool completely before removing from pan.