1. Preheat the oven to 325 degrees. Set aside a cupcake tin with liners.
2. In a mixer bowl, pour in the box cake mix and pudding mix. Then add the eggs, oil and hot water, mix together until combined. Add the sour cream and mix again. Batter will be very thick.
3. Add the chocolate chunks and fold in with a spatula until well combined
4. Fill the cupcake liners about 1/2 full. Bake for 20-22 minutes or until a toothpick comes out clean. Mine are usually done closer to the 20 minute mark.
5. Set aside on a wire rack to cool before frosting.
1. Cream the butter in a mixer for about 2 minutes on high.
2. Add the powdered sugar 1 cup at a time, leaving aside 1/2 cup. Mix on low after each added cup. Add the cocoa powder and salt next, mix well again.
3. Add the cream or milk and vanilla, mix well again. Add the last 1/2 cup of powdered sugar if you would like the frosting a little thicker. Done!