The cake is in the oven. However, I believe there must be a mistake with the conversion from cups to grams for the flour. 680 grams of flour for a cake would be enough to feed an army. I put in 300 which already seemed a lot. Also, 450 grams of sugar in a cake sounds like it would be the sweetest cake in the whole world. I put in 200 grams only. Either there is a problem with the conversion, or else North Americans eat a lot of sugar.