01 -
Preheat the oven to 350°F (177°C) and lightly grease three 12-cup mini muffin pans.
02 -
In a large mixing bowl, combine Devil's Food cake mix, eggs, canola oil, and black food coloring if desired. Mix thoroughly until a uniform dough forms.
03 -
Portion about 1/2 tablespoon of dough for each cookie and place into the prepared muffin pans. Flatten gently with your fingers.
04 -
Bake for 8 to 10 minutes until the edges are just set. Remove from oven immediately.
05 -
Using the back of a 1-tablespoon measuring spoon, press an indentation in the center of each hot cookie to form a cup. Allow cookies to cool completely in the pans.
06 -
While cookies cool, beat softened butter in a bowl until creamy. Gradually add powdered sugar, vanilla extract, and salt, beating until smooth. Add milk one tablespoon at a time until the buttercream is smooth and suitable for piping. Blend in green food coloring to achieve the desired color.
07 -
Pipe buttercream into the cooled cookie cups, filling each to resemble a bubbling potion.
08 -
Top each with round green sprinkles, Halloween sprinkles, and candy eyeballs. Break pretzel sticks in half and insert one into each cookie as a stir stick. Serve immediately.