Heat oven to 350°F. Line two cookie sheets with parchment paper.
In a large bowl, beat together the tahini, honey, egg whites, and vanilla extract with an electric mixer on medium speed. Add sugar and beat well to combine. Place the sesame seeds and coarse sugar in separate bowls.
Using a teaspoon, scoop out walnut-sized balls of dough, dip in or sprinkle with the sesame seeds and sugar and place on the baking sheets.
Bake cookies for about 10 minutes, until very lightly browned. Remove from oven and let cool 5 minutes on the baking sheet, then place on a wire rack to cool completely.