1. Grease the inside of a 6-quart slow cooker and set aside.
2. In a large mixing bowl, mix the cake mix, butter, buttermilk, chocolate syrup, eggs and vanilla. Beat on high using a hand mixer until it is well combined and no clumps remain.
3. Fold in the chocolate chips. Spread the batter evenly in the prepared slow cooker.
4. Top the batter with one can of the frosting, keeping it about an inch away from the sides of the slow cooker to prevent it from overcooking.
4. Sprinkle the coconut flakes on top of the frosting.
5. Place a layer of paper towels across the top of the slow cooker to prevent excess condensation and cover tightly with the lid.
6. Cook on high for 3 hours, until a toothpick inserted in the center comes out clean.
7. Top the cake with the second can of the frosting.
8. Spoon the cake into large serving bowls and top with ice cream.