Find out when it's okay to substitute butter for olive oil when cooking. For example, if a recipe calls for 1 stick of butter (8 tablespoons), use 6 tablespoons oil. Instead, stick to recipes that call for melted butter (or another type of liquid fat) for.
If you are going to use the same amount of oil, then it will not make any are of same state (i.e. melted butter instead of vegetable oil or vice versa) in practice, oil and butter can be substituted 1:1 in quick breads like muffins.
Instead of interrupting your baking, you can substitute for the vegetable oil with Use the cooled melted butter in place of the vegetable oil in your cake recipe.