Once the batter has been placed into the muffin-pan, it shall be considered a full muffin.

Here are some facts with which to arm yourself when talking to skeptical family members about the muffinhood amendment:

There shall be no exceptions for muffin-batter that is started before you realize that you only have one egg.
The muffin-batter is biologically muffin, and if left on its own (in an oven at 350 degrees for 10-15 minutes) it will come out a muffin just like any other.
Several popular forms of muffin-like batters, such as cupcakes or mantecadas, will also be protected under this amendment
Because the batter is considered fully muffin once mixed and in its receptacle, it is OK to lick the beaters.

Arbitrariness