Preheat oven to directions on back of cake mix box. Make cake mix. Fill cupcake liners 1/3 of the way full. Place one hershey's kiss in the center. Cover with more batter until about 2/3 full.
Bake according to directions on back of the box.
Let cool on wire rack for 5 minutes, then take out and place cupcakes on wire rack and let cool completely.
Make the frosting while the cakes cool. Cream together the butter and sugar with a hand mixer on low speed. Add in the nutella and whip on medium speed for 2 minutes. Add in the vanilla and salt, mix 30 more seconds. Add in the cool whip or cream and beat again for an additional minute until light and fluffy.
Pipe on top of the cupcakes and add a couple chocolate chips for garnish, optional.