Build a top-rope anchor off a single large tree

There is a lot of advice online on how to build a safe top-rope anchor off two trees at the top of a cliff. I have a static rope, so I would typically tie the rope around a tree, tie the other side around a second tree, and make a figure-8 master point in the center, off the edge. But what do you do if there is only a single large tree?

One option is simply tying a knot around the tree, and then tying another knot at the edge of the cliff to use as a 'master point', though this has the disadvantage of using only a single strand of rope running off the edge of the cliff. Another option is to tie two separate loops around the single tree, and make a master point between them. Both ideas are shown in my beautiful MS paint drawing below.

Are these methods safe for anchoring off a single tree? The second method seems like it should be perfectly safe to me, but I've never seen anything written about it online despite a lot of searching, so I wanted to double check.

If your tree is safe (and most big ones are) then your second method is good to go. Be sure to protect the tree. Lots of otherwise healthy trees have been damaged by careless use as anchors. 

Option 2 for sure, treat the tree like it is two separate points. Just make sure that your masterpoint wont want to the side during a fall or lowering since you don't have a triangular anchor to stabilize it.

Also, consider switching to a BHK or 2 Figure-8's / Alpine Butterflies for your masterpoint.  

Todd Jenkins wrote:

Also, consider switching to a BHK or 2 Figure-8's / Alpine Butterflies for your masterpoint.  

Would that just be for extra redundancy in case the master point loop gets cut? And its considered more important to have the extra redundancy here than on a multipitch anchor because this type of anchor would likely not be closely monitored?

Correct, redundancy, and correct, all the extra redundancy is because you're not watching it closely all day.