Preheat oven to 350°F. Place cupcake liners into muffin cups.
Place cake mix in the bowl of an electric stand mixer. Add buttermilk, oil, and eggs. Mix to combine well.
Fill cupcake liners 2/3 full and bake for 15-17 minutes. Remove from oven and set cupcakes on cooling rack to cool.
Prepare the frosting by placing the butter in a medium/large bowl. Beat the butter with a mixer until nice and fluffy. Add a small amount of food coloring.
Add the powdered sugar about a 1/2 c. at a time till well combined with the butter. Then add the almond extract and marshmallow fluff. Add more food coloring if a darker blue is desired.
Place the frosting in a 16oz frosting bag fixed with a Wilton 1M star tip. Pipe frosting evenly over cupcakes in a swirl motion and top with two candy eyeballs. Then press a cookie into the front of the frosting.