Heat oven to 350°F (325°F for dark or nonstick pan). Generously spray 24 regular-size muffin cups with cooking spray. Make cake batter as directed on box, using cake mix, water, oil, bourbon, eggs and vanilla. Divide batter evenly among muffin cups (about two-thirds full).
Bake 20 to 22 minutes or until toothpick inserted in center comes out clean. Cool in pans 10 minutes; remove from pans to cooling rack. Cool completely, about 30 minutes.
Meanwhile, for filling, in medium microwavable bowl, microwave whipping cream uncovered on High 1 minute 30 seconds or until boiling. Stir in remaining filling ingredients until chocolate is melted and smooth. If necessary, microwave on High an additional 15 to 30 seconds until mixture can be stirred smooth. Cover; refrigerate about 60 minutes or until spreading consistency.
For frosting, in large bowl, beat marshmallow creme, 1 cup butter and the vodka with electric mixer on medium speed until blended. Beat in powdered sugar until fluffy. If necessary, beat in additional powdered sugar until pipping consistency.
To assemble, cut tops off each cupcake horizontally. Spread about 1 tablespoon filling onto bottom of each cupcake; add cupcake top. Pipe frosting on cupcake tops. Just before serving, drizzle each cupcake with 1/2 teaspoon coffee liqueur.
