Knee patches are a Hungarian/Croatian fried pastry. They are basically a poor people's dessert. They are similar to some types of angel wings- Rolledthin strips that are sliced and turned inside out ( if that makes sense) and fried crispy then rolled in granulated sugar. Ours have no leavening in them. Just flour ,butter, sour cream, eggs and vanilla. Then fried in lard. They will blister up when fried and are very light. There are two camps- those who like them fried golden brown- the other likes fried dark brown. I thought I had a picture ( I always torment my cousins when I make them) but I don't. I'd be happy to share the recipe if any one is interested.
They are very plain and simple. Grandma always made them and so did mom when we had the reunions.