Ingredient: Cake flour-100g (1cup) Baking powder-1tsp(optional) Sugar- 90g (½ cup) Egg - 4 Salt - ¼ Tsp vegetable oil-70ml (1/3 cup) Orange juice - 50ml(3tbsp) Orange zest - 3tsp cream of tartar-¼ tsp(optional) Method: Separate egg whites and yolks. In a bowl mix egg yolk, orange zest, salt, ½ of the sugar, orange juice, flour and oil. Now whisk egg white, add rest of the sugar when egg white starts to foam but still liquid. Add cream of tartar and beat until stiff peak forms. Cream of tartar makes the meringue stable. Now use a spatula to fold in egg white into the flour mixture very softly. Add in 3 batches to avoid deflation of egg white. Careful not to overmix, you don’t want the air pockets to deflate. Next line a 7” pan with parchment paper. Avoid oil or butter to grease the pan. Grease-free pan helps the batter to rise properly. Pour the batter in, tap the pan on the table to get rid of big air bubbles. Preheat the oven to 175c (350f).