Spray a baking sheet wtih cooking spray. Set aside. Preheat oven to 350 ℉.
Mix dries in a large bowl. In a separate bowl, combine eggs, oil, and vanilla and mix well. Add egg mixture and sesame seeds to dries and mix well.
Place dough on floured board and knead until smooth and no longer sticky. (The dough will seem very sticky and oily at first.)
Divide dough into equal thirds and shape each into a log about 8-10 inches long and 2-3 inches in diameter. Place logs on prepared baking sheet. Press down on the logs to flatten just slightly into ovals. Can bake immediately or refrigerate until ready to bake.
Bake for 35 minutes, until lightly browned. Remove from the oven and place the baking sheet on a surface that can withstand the heat.
Using a large chef knife, cut each log into 1/2-inch slices on the diagonal. Separate the cookies just a tiny bit from each other with the edge of the knife as you cut them.
Sprinkle with cinnamon sugar and bake for 10 minutes longer.
Cool on the pan before completely separating the cookies. . Store or freeze in an airtight container. If you make them well ahead of time, be sure to bake them a third time for 5-10 minutes in a 350 F oven before serving. After this baking, they will remain crispy until they are devoured!