Line a muffin tin with cupcake liners and set aside.
Preheat oven according to cake mix’s directions.
Prepare cupcakes and bake according to the box’s recipe. Allow to cool completely before decorating.
In a medium-sized bowl, use an electric mixer to beat together butter, sugar, and milk.
Once the ingredients are well-incorporated and form semi-stiff peaks, the buttercream has formed.
Scoop buttercream into a piping bag, with a small slit cut at the bottom.
Frost the center of each cupcake, forming a peak that’s about an inch high.
Using a rolling pin, roll out the white fondant so that it’s about ¼ of an inch thick.
Use a 3-inch circular cookie cutter to cut out 12 fondant circles.
Roll out each fondant circle so that it’s about 4 ½ inches in diameter - the circle itself doesn’t have to be perfect.
Place one rolled fondant on top of the cupcake - it will fold and curve naturally but that’s okay. The beauty of these cupcakes is that they don’t need to be uniform.
For each cupcake, roll out 2 small spheres from the black fondant. Flatten each one and give them an oval shape.
Lightly brush water on the back of each black fondant piece.
Stick two on each ghost - these will act as the cupcake ghost’s “eyes.”
Serve and enjoy!