01 - Preheat oven to 350°F. Grease a 12-cup muffin pan or line it with paper liners.
02 - In a large bowl, cream the softened butter and granulated sugar until light and fluffy. Mix in the egg and vanilla extract until well incorporated.
03 - Whisk together the all-purpose flour, unsweetened cocoa powder, baking powder, and salt in a separate bowl.
04 - Gradually add the dry mixture to the wet ingredients, blending until just combined.
05 - Divide the dough into 12 even portions. Roll each portion into a ball and press it into the bottom and sides of the muffin cups to create a well.
06 - Bake for 13–15 minutes until set. If the centers rise, press down lightly with a spoon immediately after baking. Let cool completely in the pan.
07 - Melt the chocolate chips in the microwave or over a double boiler. With a spoon or pastry brush, coat the inside of each cooled cookie cup to resemble a cauldron. Allow the chocolate to firm up.
08 - Pipe the colored frosting into each chocolate-lined cup. Arrange assorted candy bubbles on top to mimic bubbling potions. Sprinkle with edible glitter if desired.
09 - If desired, insert a curved piece of black licorice lace into both sides of each cup to form handles.
10 - Present your edible cauldrons and enjoy.