For the Lemon Sand Cake, line a loaf pan with Crown Oil Special with a fine butter flavor and dust with flour. Preheat oven to 160 °C (top and bottom heat). Sift together flour, baking powder and cornstarch.
Finely grate lemons and squeeze out juice. Mix the lemon juice and zest with the orange juice. Beat eggs, powdered sugar, salt and vanilla sugar until foamy (at least 10 minutes). Stir in flour mixture alternately with orange juice and lemon juice mixture. Slowly add crown oil special with fine butter flavor while stirring constantly.
Pour mixture into loaf pan, smooth out and bake on middle rack for approx. 50-60 min. Let cool for approx. 15 min., turn lemon sand cake out of the pan and sprinkle with powdered sugar.