Add sugar and water to a nonreactive pot over high heat, stirring just until the sugar dissolves.
Once the mixture comes to a boil, stop stirring completely and clip on your candy thermometer.
Let the syrup cook undisturbed until it reaches 300°F, about 20-30 minutes.
While you wait, prepare your ice bath and set it nearby.
Working quickly one at a time, submerge each sweet roll completely in the candy syrup, then use a long skewer to remove them from the sugar mixture, letting any excess drip off.
Immediately plunge each coated roll into the ice bath to set the coating.
.ransfer to a parchment-lined plate to cool completely.
Meanwhile, divide your prepared vanilla pudding into separate bowls and tint each with pastel food coloring.
Transfer each color to its own piping bag fitted with a small round tip.
Using a skewer or small knife, poke a hole into the bottom of each coated roll and pipe in your pudding filling until you feel slight resistance.
Serve immediately for the best crack.