Preheat oven to 350 degrees F
Spread sesame seeds in 9x9 inch baking pan. Toast in the oven for 10 to 15 minutes. Remove from oven and cool.
Make the flax egg with the flax and water. Let gel for 5 minutes.
Cream the margarine and sugar until combined, add the flax egg.
Stir in the lemon rind, sesame seeds, flour, and baking powder.
Drop by 1/2 teaspoonfuls onto cookie sheets, leaving about 2 inches between each cookie.
Bake for 10 minutes or until golden brown. Cool for a few minutes before removing from cookie sheets. Cool cookies on wire racks.