Kek Coklat Nisah

1 cup gula kastor
250 gm mentaga
1 ts esen vanila
1 ts ovalet
1 ts choco paste
1/2 sup susu pekat manis
4 biji telur
1 1/2 cup tepung gandum
1 cup coco powder
1 ts serbuk penaik
sedikit bikarnobate soda