Turn the mixer down to low, and add in the egg yolk, and vanilla. Beat well.
With mixer still running on low, sprinkle in the remaining dry ingredients one at a time, in the order they are listed. Hold off on the jelly and nuts at this point! Dough will be stiff.
Grab about a tablespoon of dough and roll into ball. Continue until you have rolled them all. If dough seems overly soft and warm, chill the balls for 10-15 minutes.
If you are using nuts, now is the time to roll the balls into the finely chopped walnuts. With no egg, you roll firmly to gently press the nuts slightly into the ball, OR roll in the whipped egg white first, then roll in the nuts.
Recipe via tessadomesticdiva.com