Purpose

• Vegetable oil is used in cake mix to add moisture and texture to the cake. Without the oil, the cake will be dry and crumbly. Mayonnaise is thick, creamy and made from an oil emulsion; therefore, it is a suitable substitute for oil in a cake mix.

No Egg Method

• When using mayonnaise instead of oil in a cake mix, you can also omit the eggs because mayonnaise contains eggs. Use the same amount of mayonnaise as the amount of oil required in the instructions, but omit the eggs. Mix the cake mix with the mayonnaise. Measure out the water according to the recipe, but add it in slowly -- just enough to get a cake batter texture. Don’t add more water than the recipe requires. Increase the baking time by 5 to 10 minutes to compensate for the mayonnaise.

Egg Method

• You can still use eggs and mayonnaise in the same recipe for a richer, lighter cake. Substitute 1 cup mayonnaise for oil with a 16.5 ounce cake mix. Follow the recipe for eggs and water amounts. You may need to increase the baking time to compensate for the additional liquid, but this depends on the cake mix type. Check the cake at the indicated time and increase baking time if necessary.

Considerations

• You won’t taste the mayonnaise in your cake as long as you use a basic mayonnaise without additional seasonings. You can use mayonnaise made with vegetable oil or olive oil, but mayonnaise with olive oil may produce a moister cake than mayonnaise with vegetable oil. Mayonnaise cakes are denser than cakes made with oil, but still have a light crumb. Because they’re so moist, chill the cake in the refrigerator or freezer before frosting it so that your cake doesn’t tear or crumble in the process.