Preheat oven to 350 degrees. Grease a 10 x 15 inch jelly roll pan with butter, line with parchment paper then grease the top of the parchment. Set aside.
Combine flour, ginger, cinnamon, cloves, nutmeg, baking powder and sea salt in a mixing bowl. Whisk until combined then set aside.
In a separate bowl, beat egg whites with a whisk attachment until soft peaks form. Add granulated sugar then beat until peaks stiffen. Set aside.
In a separate bowl, beat egg yolks until until thickened, approximately 2 minutes. Add dark brown sugar, molasses and vanilla and beat until combined.
Add flour mixture to the egg yolk mixture, stirring with a spoon until combined.
Gently fold in whipped egg whites.
Pour batter into prepared jelly roll pan. Smooth with a spatula then bake for 8 to 10 minutes. Cake is done after it springs back when pressed with a finger.
While cake is baking place a tea towel on your counter and generously dust with powdered sugar.
As soon as cake comes out of the oven, turn it onto the tea towel to release from pan. Gently remove parchment paper then roll the warm cake with the tea towel starting with a short end.
Refrigerate towel-wrapped cake for 3 hours.