“If you want to make an even softer and fluffier cake with a greater rise, and one that stays softer for longer, you can substitute half of the butter for a neutral-tasting oil, such as sunflower, vegetable, or canola oil. ... Regular dairy butter is composed of about 80% fat, 15% water, and 5% milk solids - so when you're swapping butter for oil, it's not a 1:1 substitution. Instead, you need to replace the butter with 80% of oil and 15% of milk.” Science Book:The Elements of Baking By Katarina Cermelj & Crazy For Cookies Brownies & Bars By Dorothy Kern 2 Books Collection Set Source: The Elements of Baking By Katarina Cermelj & Crazy For Cookies Brownies & Bars By Dorothy Kern 2 Books Collection Set