In the bowl of a stand mixer, mix cream cheese and butter until smooth and creamy. Add vanilla. Mix in powdered sugar and cocoa powder on low, increasing speed until completely combined.
Making the Spooky Cupcake:
Use a paring knife to core each cupcake leaving a layer of cupcake at the bottom (see video). Set the top of the core aside and do not discard.
Fill each cupcake with candy.
Replace core and frost. For these cupcakes, I used a large closed star tip. Start at the outside and pipe a swirl, ending by releasing pressure and lifting straight up from the center.
Top with sprinkles. Don’t wait more than a few hours before serving, or the candies will soften and taste funny.