Preheat oven to 350°F (176°C) and line a muffin pan with liners. This recipe makes 24 cupcakes. Set aside.
In a large bowl, whisk the eggs with a fork. Add in the sour cream, canola oil, and vanilla extract. Stir until completely combined. Add cake mix and pudding mix, stirring a few times to moisten. Add the hot water and mix until just combined. Fold in the chocolate chips. If you’re using chopped chocolate instead, chop it pretty small to about the size of mini chocolate chips.
Fill the cupcake liners 3/4 full. Bake one tray at a time for 18–23 minutes, or until a toothpick inserted into the center comes out clean or with a few moist crumbs. The tops should bounce back when lightly touched. Remove the cupcakes and let cool in the pan for 5–10 minutes before transferring to a wire rack to cool completely.
Frosting
Using a handheld or stand mixer fitted with a paddle attachment, beat the butter in a medium bowl on medium speed for 3–4 minutes. Add powdered sugar, cocoa powder, and salt. Mix on low. Add the heavy cream and vanilla extract. If frosting is too thin, add up to 1 cup of additional powdered sugar until you get the desired consistency. If frosting is too thick, you can add up to 2 tablespoons of additional heavy cream. Add in the salt. If frosting is still too sweet, add a dash more salt.
Transfer the frosting to a piping bag fitted with a star tip and frost the completely cooled cupcakes. Cupcakes are best enjoyed with 1–3 days.
Video
Notes
Note 1: The cupcakes need to be elevated on a wire cooling rack so air can circulate around all sides as they cool. Otherwise, moisture will condense on the bottom of the cupcakes, making them damp and slightly sticky.Mini Cupcakes: Line a miniature muffin tin with liners and add about 1 rounded tablespoon batter into each. Bake for 10–15 minutes or until a toothpick comes out clean or with a few moist crumbs. Repeat with the remaining batter.Storage: Store cupcakes in an airtight container at room temperature. To freeze unfrosted cupcakes, cool completely, then place on a sheet pan in the freezer for 30 minutes. Wrap each cupcake individually in plastic wrap and transfer to large freezer bags; store for 2–3 months. Thaw at room temperature, then frost as desired. They will be slightly more moist but still delicious!