This is seriously one of the quickest, easiest recipes a person could ever make and is about 1/2 a step up from just making a plain box of Jell-o. It's been around for quite a while, as evidenced by the cute 1960s style ads describing how to make it. My one change was to use the drained pineapple juice in the Jell-o instead of just dumping it and using water. I've included that in the directions below, because the added pineapple juice really punched up the flavor. My husband and I both really enjoyed them, much more than I expected.
As adorably tacky as these pineapple rings are, I'll probably make a can with lime Jell-o and a can with cherry Jell-o for Christmas. How cute would they be arranged in alternating colors in a spiral on a platter?
Quick Note: I suggest using name brand pineapple vs store brand. We tried it both ways and liked the name brand better. We also tried both strawberry and lime Jell-o and preferred the lime.
Jellied Pineapple Rings
20 oz can pineapple slices
3 oz box Jell-o powder (I used lime)
Drain pineapple juice from can into a measuring cup. Add enough water to it so that you have 1 cup total liquid. Bring liquid to a boil in a small sauce pan, remove from heat, and stir in the Jell-o powder until completely dissolved. Pour Jell-o mixture over the pineapple rings. You will have some Jell-o mixture left over, just pour that into an extra bowl to enjoy as a snack. Place the can of pineapple rings and bowl of extra Jell-o in the refrigerator to solidify. This will take several hours.
When you're ready to eat the pineapple, dip the can into a bowl of hot water for about 10 seconds. Flip it upside down over a plate and open it from the bottom with a can opener. If the can is the traditional style that you had to open with a can opener, you can just gently push/shake the pineapple out of the top of the can. If the can is the newer style with the pull tab, flip it right side up again and gently push/shake the pineapple slices out the bottom of the can onto the plate. You want the pineapple to come out the bottom of the can because they will get mangled if they come out the top, since pineapple cans have the pull tabs and are slightly narrower at the top.
Gently slice the rings apart with a knife, and serve.