I did everything wrong from accidentally melting the butter when trying to soften it in the microwave (put it in the freezer for a few minutes afterwards) to most likely curdling the sugar
mixture when I added the yogurt (the low fat kind) to yanking the
muffins out
of the oven 5 seconds after I put them in there hoping like crazy that the thought
of rising hadn't even entered their little
muffin heads yet while I dumped brown sugar
over the
tops.