You need a fertilizer with a higher nitrogen content for the growth period. something like 30-15-5. I agree, you need to find plant food that's geared towards Cannabis. Foxfarm has really good product.

Also, keep your light cycle consistent. Usually for veg you need an 18-6 light to dark and then switch to 12-12 for flowering.

And in conclusion - on the Molasses - Make sure it is black strap/unsulphured molasses. Plantation is usually the best and is completely organic. It has all the nutrients your plants need for denser and bigger buds. You can purchase it at any health food store. I got mine at Wildly Natural Foods here in Farmington.