This tried and true whipped chocolate buttercream recipe is the perfect cake filling, or cupcake frosting! It pipes well, and tastes amazing.
Begin by melting the cup of chocolate chips. Heat it in the microwave for 1 minute at half power in large heat proof bowl, or over a double boiler.
Stir until smooth, then set aside briefly to allow it to cool just a bit (not more than 5 minutes).
In the bowl of a stand mixer, beat the butter on a medium speed for 30 seconds with a whisk attachment, until smooth.
Slowly add in the powdered sugar, 1 cup at a time. Alternate with small splashes of cream.
Scrap the sides of the bowl with a spatula, to ensure all the powdered sugar is mixed in.
Add in any remaining heavy cream, then whip on high for about 1 minute.
Next, add in the melted chocolate. Beat on high again, until the chocolate is fully incorporated.
Pour in the egg whites, and beat on high again for about 30 seconds.
Add in the salt, and mix until fully incorporated. The frosting should be rather thick, like whipped topping!
If yours isn't as thick as you'd like, place the bowl in the freezer for about 5 minutes, then beat on high again for about 1 minute.