Preheat oven to 350 degrees F. In a stand or electric mixer beat cake mix, oil, water, eggs, sour cream and pudding on medium speed for 2 minutes. Stir in cinnamon chips on low. Fill 24 traditional cupcake size cups ¾ full. Bake for 25-30 minutes or until toothpick comes clean from center. Remove and let cool completely.
Place caramels and milk into a medium saucepan over medium low heat until melted and smooth, stirring constantly. Remove from heat and cool for 10 minutes. Place egg yolks and powdered sugar into a stand mixer with the whisk attachment. Whisk until well combined. Slowly beat in melted caramel until well combined. Transfer to a covered bowl and refrigerate until chilled, a couple hours or overnight. When chilled, beat butter and caramel in a stand mixer until whipped. Slowly beat in powdered sugar until fluffy. Spread on cooled cupcakes and serve.