It's a dragonfruit, pitaya undata. Flowers then Fruit come out the side of the pad. This pad grew this month and is the only one that has these on it. Apparently this one self pollinates and the fruit is sweet. It's alien like!
Yes, those are aerial roots. Let me guess, they're on the side away from the sun. The plant is reaching out to grab on to something so it can keep growing up. The flower is very different. It looks a little like a new branch when it starts out, comes out of the apex, opens at night.