Whip the egg yolks, 85 grams of the granulated sugar, and vanilla on medium until thick and light in color, about 10 minutes.
Whip the egg whites on medium speed until frothy. Gradually add the remaining 85 grams of granulated sugar while continuing to whip, then whip until medium peaks form.
Gently fold in the remaking egg whites to the egg yolk mixture.
Gradually fold in the sifted flour.
Spread the batter in the prepared sheet pan.
Bake immediately at 400°F until the cake springs back when touched, about 7 - 10 minutes.
Run a pairing knife along the edge of the sheet pan, to help separate the cake. Sift powdered sugar on top and place a tea towel over the cake. Place another sheet pan or cutting cboard, and invert the cake, then use the towel to help roll the cake.
Let the cake cool completely before unrolling it.
For Chocolate: Reduce the flour to 128 gram s and add 43 grams of Dutch processed cocoa powder. Sift the flour and cocoa together. Follow the remaining method as stated above.