Preheat oven to 350. Grease three 9 inch round pans. Sift flour, salt and baking soda together and set aside. If using cocoa powder mix that with the dy ingredients too.
Melt semi-sweet chocolate with 1 tablespoon of milk. Set aside but do not let harden. Or if you are using coca powder just sift it in with the flour mixture.
Beat butter and sugar in a bowl together for approximately 5 minutes at medium speed. Add eggs one at a time and beat until smooth. Add the food coloring and sour cream, milk vanilla and butter flavoring and chocolate squares. At low speed add flour mixture a little at a time but do not over mix.
Bake in 350 oven for 35 to 40 minutes or until wooden pick comes out clean.