For ingredients part 1: Sift the cake flour, sugar, baking soda, baking powder and salt together. Set aside.
For ingredients part 2: Mix ingredients part 2 in the bowl. Stir all ingredients thoroughly. Set aside.
For ingredients part 3: Beat the white eggs with medium speed until it gets frothy. Add cream of tartar and beat with high speed. Gradually add sugar and beat for a minute. Set aside.
Pour the ingredients part 1 into the ingredients part 2 and stir all together. Add the ingredients part 2 into the same bowl. Stir all together with hand whisk softly.
Transfer to cake pan (size 2 pounds) and bake for 30-35 minutes. Set aside. (If you use the half-circle tray or orange shape tray, this will take 18-20 minutes to bake) Set aside
How to make orange sauce topping
Mix all ingredients into the pot except the salted butter, heat until boil.
Turn off the heat, add salted butter and stir well.
Pour the orange sauce all over the cake for the final top.
Let it set for 15-20 minute in the fridge. Serve chilled.
