Preheat oven to 350 degrees F.
Spray 2 (9-inch) round cake pans with nonstick cooking spray.
In a large bowl, cream together butter and sugar.
Beat in eggs, one at a time.
Stir in greek yogurt (or sour cream), buttermilk and food coloring until combined.
Mix in salt, baking soda, cocoa powder and flour until combined.
Pour batter into cake pans and bake for 35-40 minutes or until an inserted toothpick comes out clean. Let cool completely.
In a large bowl, beat together cream cheese, butter, sour cream and vanilla until fluffy.
Beat in powdered sugar until smooth.
Frost cake as desired.
Use a vegetable peeler and a chocolate candy bar to create chocolate curls for garnish.