Can someone help? I would like to make the # 1 out of fondant for a topper on a cap. I rolled it like you would a border and shaped it into the number, but is it going to dry stable enough so that I can put it on top? And how should I attach it?

Put a toothpick or lollipop stick into it before it hardens, and once it's all the way dry you can just poke the toothpick into the cake to attach the number. It should dry hard enough, depending on the size it might take a couple of days.

Next time if you knead a bit of tylose powder or GP into your fondant it will dry harder and faster.

Tex is right though, a toothpick or a lolly stick will work just fine. If your number is really tall you can use a thin skewer or dowel.

I let mine dry for several days and I don't use tylose. If I need it sooner I put it in my food dehydrator. To attach it to the cake you can use the toothpick or lollipop stick or even a bamboo skewer. If I don't do it before the # hardens I just use melted white chocolate to attach a skewer or lollipop stick to the # and it works great. Not as pretty from the backside, but it's stable.

I actually went out and bought one just so I'd have it for fondant pieces... LOL