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.