Heat the oven to 350 degrees and spray a bundt pan with non-stick cooking spray.
Mix the butter, sugar, and vanilla together until fluffy. Slowly add the eggs and beat well.
In a separate bowl, combine the flour, 1 teaspoon baking soda, and salt. Add this mixture to the butter mixture, alternating with the buttermilk. Beat until well combined.
In a small bowl, mix together 2 cups of batter, the chocolate syrup, and the remaining baking soda and set aside.
Pour the plain batter into the bundt pan, followed by the chocolate batter directly on top. Do not mix them together.
Bake for 60-65 minutes, or until a toothpick comes out clean. Cool for 15 minutes and remove from pan to cool on a cooling rack.
Mix together all the frosting ingredients, slowly adding the milk 1 tablespoon at a time until you reach the desired consistency.
Once the cake has cooled, frost the cake as desired and serve. Enjoy
*Nutritional information is a calculated guesstimate. Please note that this can change with different brands and modifications you may make to the recipe. For the most accurate information, use a nutritional calculator with the exact brands and measurements you're using with each recipe.