Measure out all the ingredients for your Halloween version of monster cookies. Add the dry ingredients into a medium bowl and mix together.

Next, add the wet ingredients into a small bowl. Beat the egg, milk, and unsalted butter together. Ensure there is no eggshell in the mix.

Combine the dry and wet ingredients (milk, vanilla, and egg) together. Mix and knead into cookie dough.

Cut out your Halloween cookies using a round cookie cutter with patterns for Halloween monster cookies. If you don't have a cookie cutter, use a cookie scoop or make cookie mounds or balls to place on your baking sheet.

Place the cookies on a cookie sheet lined with parchment paper. Bake at 180°C for 10-12 minutes. Once cooked, all them to cool completely.

Mix together the powdered sugar, unsalted butter, heavy cream, vanilla, and salt until creamy. Add food coloring for desired monster cookie color.

Using a piping bag, add the filling onto one cookie. Top with another cookie and press down lightly. Add candy eyeballs with a dab of the filling for a spooky touch.

Serve and enjoy these Chocolate Halloween monster cookies at any Halloween party or gathering, and don’t forget some for the trick-or-treaters!