I have not really every done decorated cookies before. I need to help with a good recipe and icing. This will be done with a #3 cutter and decorated for 3 year olds. I dont want the icing to be super hard but it need to be hard enough that i can put in a bag.

thanks in advance

If it's for little kids, I would suggest regular buttercream. I have a student with a toddler with the same request you have and she did pumpkin cookies with buttercream and an offset spatula in orange buttercream, then did green buttercream leaves and vines. Very easy design for the little ones.

the glace GeminiRJ uses hardens enough to stack, but soft enough not to break your teeth!

I have a 3 and 5 yr old and we did NFSC and 'painted' on icing for Christmas. I found a recipe on line that was just really just watered down RI. It worked great. My 3 yr old handled the paintbrush with no problem. Then we just stuck on some sprinkles and such. I stuck to a couple of colors (mostly red and white) or the colors run a bit. But it was successful and less messy!