In short: yes. But the amount of THC in the leaves is so low that you would need a HUGE amount. And if you have that much, you would really be better off making bubble hash w/ trimmings. But yes, if you somehow managed to get a quarter pound or so of leaves, you could cook with them, but you better be one hungry mamma-jamma, because you're going to need about 5 sticks of butter to get the effects. Not really worth my time personally, but it's up to you.