Preheat oven to 350°F and line two baking sheets with parchment paper.
In mixer with paddle attachment, combine eggs, egg yolk, and 2 teaspoons of sugar. Mix on high speed for 10 minutes.
While the eggs are beating, whisk together the cake meal and potato starch in a small bowl.
Reduce the mixer speed and pour in the oil and vanilla extract. Mix on high until all ingredients are fully combined, 3-5 minutes. Make sure the oil is fully emulsified into the egg mixture. If you see any signs of oil, keep beating.
Reduce mixer to low speed and mix in dry ingredients until they are fully absorbed. Increase the mixer speed to medium-high or high and keep beating. You may have to stop the mixer to scrape down the sides of the bowl a few times. Beat for 3- 5 minutes. The dough should feel slightly wet, but not sticky.
Liberally spread approximately ¼ cup sugar on parchment paper set on countertop. (You can do this directly on the countertop, but it makes for a much easier cleanup to do it on parchment paper.) Use a rubber spatula or bowl scraper to scoop the dough onto the top of the sugar. Liberally spread an additional ¼ cup of sugar on top of the mound of dough. Roll dough to approximately ¼ inch thick, using a bench scraper to guide the dough to create and maintain a rectangle, approximately 7 inches by 12 inches. Continue to coat the dough using as much of the remaining sugar as necessary (top and bottom) while rolling out the dough.
With a pizza cutter or a knife, cut rectangles, 1 inch by 2 inches. (Make 1 inch cuts along the side of the dough that is 7 inches, and make 2 inch cuts along the side of the dough that is 12 inches.) Carefully twist each rectangle in the middle. Place on prepared baking sheet, 2 inches apart from each other. Bake in the center of the oven. Bake for 45-50 minutes, but check them at the 20 minute mark and then the 30 minute mark, as ovens vary. (If they are done in 20 minutes, it means you probably did not mix the ingredients long enough before shaping.) They are done when the edges and bottoms are deep golden brown. You can always break one apart to make sure the dough is no longer soft in the middle. Allow to cool completely, leaving them out at room temperature for several hours.