Knead almond paste until soft; work in powdered sugar.
Add vanilla and salt.
Add egg whites, a little at a time, blending well after each addition. Use just enough egg whites to make a soft dough that will hold its shape when dropped from a teaspoon.
Line cookie sheets with unglazed brown paper.
Drop paste onto sheets by teaspoonfuls, about 2 inches apart. Or force through a cookie press into rounds.
Sprinkle with sugar.
Bake about 20 minutes at 300 degrees.
Place macaroons on damp towel to loosen the brown paper and remove paper. Cool on racks.