vegan butter substitute for cookie baking?

[eppur_se_muova]

9. I posted this earlier, but still haven't found the link to the sweet potato/carrot solution ....

https://www.democraticunderground.com/115755425#post3

ETA: Whoops, this looks like it -- only subs for 2/3 of fat/lard/butter: https://www.food.com/recipe/sweet-potato-carrot-fat-substitute-for-recipe-347628

Might want to look at the original link in my earlier post for the discussion, not a particular recipe -- https://cooking.stackexchange.com/questions/13165/what-is-the-best-vegan-substitute-for-lard

I went to a site that sells vegan spreads etc. and searched for "sour cream" -- the only result was for a recipe that called for sour cream ! (BTW, most of the acids in sour cream bake out, so you could probably substitute another source of dairy fat, such as heavy cream. I think sour cream is traditionally used in Eastern European cooking because it didn't spoil as fast as fresh cream (??). The sourness is mostly acetic and butyric acids, which are volatile.

Smetana

Smetana is a range of sour creams from Central and Eastern Europe. It is a dairy product produced by souring heavy cream. It is similar to crème fraîche, but nowadays mainly sold with 10% to 30% milkfat content depending on the country. Its cooking properties are different from crème fraîche and the lighter sour creams sold in the US, which contain 12 to 16% butterfat. It is widley used in cooking and baking.

And yes, that is the last name of the composer -- Bedrich Smetana.