In a mixing bowl cream sugar and margarine or shortening until fluffy. Add egg (or flax replacer) and flavoring and beat well.
In another bowl combing the flour blend, xanthan gum, salt and baking powder. Mix well. Add to sugar mixture in mixing bowl. Beat until combined. Scrape down mixing bowl and mix again until all combined.
Roll 1 inch balls of un-chilled dough into balls then roll in the finely chopped nuts. Place dough on baking pan and press the tip of thump into center of dough to create an indent. Bake for 6 minutes. Take pan out of oven an push down on indents, if needed, bake for 2-4 more minutes. Allow cookies to cool for 5 minutes on baking sheet before moving to cooling rack. Fill indent with fruit juice sweetened jelly or jam.