Preheat oven to 375˚F (190˚C). Stir together cookie mix, butter, cocoa powder, milk and egg until combined; shape dough into 24 balls and place into ungreased mini muffin pan.
Bake for 8 to 9 minutes or until edges are lightly golden and dough is cooked through. Immediately press indentation into each with end of wooden spoon, pressing gently against edges to create “cauldrons.” Let cool completely in pan. Remove from pan and transfer to serving tray.
In microwave-safe bowl, combine toffee pieces and corn syrup; microwave on medium for 1 or 2 minutes, stirring every 30 seconds, or until smooth and melted. Drizzle into cookie cauldrons. Fill each cauldron with 5 SMARTIES. Using round edge of skewer, poke hole on each side of cauldron; insert ends of licorice whip into holes to create rounded handle. Insert pretzel stick into each cauldron as a broom handle. Let cool completely.