better butter

How Much Butter Do I Use Instead Of 1/2 Cup Oil? In cooking, for 1/2 cup of oil, you can use 2/3 cup of butter. How do I substitute butter for oil in a cake? Bread, Muffins, Rolls, Cakes, Cupcakes – A 1:1 substitution usually works well (1 cup oil for every 1 cup butter).