If it's powered agricultural molasses vs unsulphured table molasses it's different. With feedings is appropriate. However I stopped using it. Didn't notice any difference.
The powdered molasses I would use alone. In between feeds. For veg and half of flower. Again. Noticed nothing.
I could be wrong, but I believe molasses cured an iron deficiency I had once. But I can't say I've ever noticed any other effect. The best I can say is 15 ml dissolved in a gallon of water definitely won't hurt the plants.