double pane insulated window??? cold at night.. might be making a natural curl.. worse ... regardless.. that is some great lush vigorous growth.. so it cant be getting too cold at night ... let me put it this way.. if there was anything wrong.. it wouldnt be growing that vigorously ... eh?? if it is sprouting roots in mid air... i will guess you could cut the above off.. root it.. give it to a friend [hence the name] .. and yours will rebud below the cut.. anyone want to confirm or destroy that guess??? ken

Possibly Yucca elephantipes. If so only hardy in zones 9-11. You could get confirmation or other suggestions if you post this to Name That Plant

It's an agave flower spike....yet to flower.

I thought peperomia too but usually the inflorescenses of peperomia are singular rather than one splitting into multiple. But that is why I asked if there were ever actual flowers on those spikes. If the answer is no, then they do seem to be inflorescences which would be indicative of peperomia of some sort.