Nope! Dan Anderson's math class decided to get to the bottom of the Double Stuf Oreo debate. Are they really "double" the amount of cream? According to their findings, the Double Stuf Oreo's are only 1.86x as big as regular Oreos.
They also tested the newer Mega Stuf Oreos. Those were 2.68x as big as regular Oreos. So if you're looking for a true double stuf Oreo, go with the Mega Stuf.