Make up the donut mix according to manufacturer’s instructions. Fry and let cool completely. Fill with Bavarian creme filling.
How to make the caramel:
Add sugar to a non-reactive saucepan (without a non-stick coating). Any amount of sugar is fine, just make sure it is no more than ½ inch thick on bottom of pan. Give the pan a shake to spread the sugar in an even layer, then place over medium high heat to melt. The sugar will start to melt and caramelize at the edges of the pan first. Once the edges of the sugar are caramelizing, use a wooden spoon and start bringing the caramelized parts into the middle of the pan, to where the sugar hasn't melted or caramelized yet. Keep stirring until all the sugar has melted and caramelized. Squash stubborn sugar lumps against the sides of the pan if necessary. Cook the caramel until it turns a rich brown color. Once the caramel has turned a deep amber color, stop the caramelization process by dunking the bottom of the pan in an ice water bath. Do this quickly as leaving the pan in the cold water bath will harden the caramel. Wearing gloves, carefully dip the tops of each donut into the caramel, place on a sheet tray to set up. Do not touch the caramel as it is very hot. Once cooled, the caramel will become crispy.
To clean the pan afterwards, simply fill with warm water, place over low heat, and allow the water to come to a simmer. The caramel will melt.