All carrot cake recipes require some type of fat to influence the texture, shape and moisture content of the finished cake. Thankfully, you can choose from a handful of substitutes if you don't have vegetable oil at home. Other types of cooking and baking oils work well and even butter can work.

Canola oil works as a substitute for vegetable oil because this type of oil has similar properties and it's listed as another type of vegetable oil. The oil looks similar to vegetable oil because it has a thin consistency. The oil is made from tiny canola seeds, contains vitamin E and is cholesterol free.

Extra-virgin olive oil works well as a substitute for vegetable oil because it has a similar texture when compared to vegetable and other types of oils. Extra-virgin olive oil is thinner than other types of olive oil, so it looks similar to vegetable oil. Extra-virgin olive oil also contains more nutrients than vegetable oil. Olive oil contains healthy fats such as omega-3 fatty acids.

Like olive oil, grapeseed oil can also work as a vegetable oil substitution. This oil has been pressed from the seeds of grapes. It contains healthy omega-3 fats that make it healthier than standard vegetable oil. Grapeseed oil has a light, fresh taste that won't change the overall taste of the recipe too much.

Melted butter can also work as a substitute for vegetable oil when making a carrot cake. Melt the butter until your measuring cup is full of the amount of vegetable oil for which the recipe calls. You might need to melt additional sticks of butter to equal the total amount needed. This substitution works well, but it takes additional time to get the right amount.