Preheat your oven to 350°F (175°C). Prepare your chocolate cake mix according to the package instructions, then pour the batter into lined cupcake tins, filling each cup about two-thirds full. Bake for 18-22 minutes until a toothpick inserted in the center comes out clean. Let them cool in the pan for a few minutes before transferring them to a wire rack to cool completely.

While the cupcakes cool, whip up your Best Buttercream Frosting. Follow your favorite recipe or package instructions to ensure it's smooth and creamy. Reserve about ¼ of the frosting for later use, and tint the remaining frosting with red food coloring until you achieve a vibrant shade that resembles Santa's hat.

Twist open 18 Mini Oreo cookies, discarding the creamy filling, and keep the chocolate wafer halves aside for decorating. These will be used for Mickey’s ears.

Fill a pastry bag with the red buttercream frosting, then pipe a swirl onto the cooled cupcakes to create a whimsical Santa hat shape. Start from the middle, working outward, and create a nice peak at the top.

Change to your Wilton #22 star decorating tip, fill your pastry bag with the reserved white buttercream frosting, and pipe a decorative band at the base of the red frosting.

Using the white frosting, pipe a small dot at the tip of each cupcake to mimic the ball on Santa's hat. Press two Mini Oreo cookie halves into the frosting just below the hat peak to make Mickey's ears look charming.

Use white buttercream to pipe small dots onto the red cupcake liners, simulating buttons on Santa's outfit.