Very cool! Have you replaced avocado for butter in anything else? The other day I tried a recipe that used greek yogurt instead of butter/oil in some cookies and it was a pretty big fail.
Sorry for not replying sooner---I have been MIA on craftster as of late. I haven't tried subbing avocado for butter in any other recipes. I have had good luck subbing apple sauce for butter and coconut oil (1/2 the amount of butter will do, so 1 cup of butter would translate into about 1/2 cup coconut oil), though.