Preheat oven to 350. In a small bowl, microwave 2 sticks of the butter on HIGH 1 minute or until melted. Slice remaining butter into 1/2 inch pieces; add to melted butter, tossing to coat. Allow butter to stand 3-5 minutes or until softened.
Meanwhile, in large bowl, combine cake mix and flour; blend until smooth and free of lumps. If necessary, mirocwave butter an additional 10-20 seconds or until creamy and pourable. Do not melt completely.
Pour butter, all at once, into dry ingredients, scraping butter from bowl. Mix until dry ingredients are incorported and dough is smooth. (If dough is too stiff to stir, knead by hand until smooth.)
Refrigerate if necessary.