01 - 
                Preheat oven to 350°F (175°C) and lightly grease three 12-count mini muffin pans.
              
              
              
                02 - 
                In a large bowl, combine cake mix, eggs, oil, and optional black food coloring until smooth.
              
              
              
                03 - 
                Scoop 1/2 tablespoon of dough into each muffin cavity. Flatten tops and bake for 8–10 minutes until edges are set.
              
              
              
                04 - 
                While warm, press a 1 tablespoon measuring spoon into the center of each cookie to form a well. Cool completely before removing.
              
              
              
                05 - 
                Beat butter until creamy. Gradually add powdered sugar, vanilla, and salt. Mix in milk until piping consistency forms. Tint with green coloring.
              
              
              
                06 - 
                Pipe green buttercream into cooled cups to resemble bubbling potion.
              
              
              
                07 - 
                Top with green sprinkles, Halloween sprinkles, and candy eyeballs. Insert halved pretzel sticks to mimic stirrers.