carbohydrates??

Ive heard that eating large amounts of carbohydrates, eg rice or spagetti before sleeping increases serotonin
is this true??

Carbohydrates do help produce serotonin, don't know whether you need to eat them right before bed, or if just eating enough in the day will work though.

it said eat it b4 u go to bed b/c serstonin helps you sleep.

You will get better results from eating particular foods such as bananas and turkey than simply large amounts of carbohydrates. Check out this thread for more details.
If you can source 5-HTP it will restore your serotonin levels substantially faster than relying on food. It can be ordered online - click here for cheap places to order from.
And lastly, ideally on top of either or both of the above you should also take at least a month break between MDMA use.

Carbohydrates are a source of tryptophan, an amino acid which is a precursor to serotonin. Apparently eating carbohydrates alone, without any protein, is the best way to get maximum serotonin production, as other amino acids found in protein will compete with tryptophan for uptake from your bloodstream to your brain. See Neurotransmitter Precursors.
As for how quickly this occurs, I seem to remember reading that tryptophan tablets take about 6 hours to be converted to serotonin, but I'm damned if I can find the reference (it was probably some dodgy health food store or something).

Turkey meat and bananas are good for this too...

^^^^^
That'll teach me to skim read...