Muffin Help --- Ideas Please!

Hello! I'm in the middle of my freezer cooking day. All of the chicken breasts have been trimmed. Some are in the crock pot for the Enchiladas and the rest are portioned out into freezer bags awaiting marinades. My bread dough is rising and about to be rolled out. The sauce is ready for Lasagna.

 
Here's where I need help .... I doubled my Zucchini Bread recipe and I am using the batter to make muffins. I know am pretty sure that I doubled everything.  These 2 muffins were side by side in the muffin tin.  One looks perfect while the other looks like a souffle that rose and deflated.  And there are others just like each of them.  Any idea why??

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