Yeah, they're a healthier option than a lot of processed fats. Personally I think fats are NOT the enemy - if you're making a cake and use a pure minimally processed vegetable oil or even decent quality butter without additives and you know exactly what's going into your cake, then it's totally fine so long as you eat it in moderation rather than the whole cake... which I know can be problematic But avocado is definitely a great alternative, and I've seen quite a lot of recipes that use it for desserts! Could you taste it at all in the cake?