Cream the Butter: In the bowl of a stand mixer fitted with the paddle attachment, cream 1 cup of butter on medium speed until it's creamy and smooth, taking about 2-3 minutes.

Add the Sugar: Add 3 cups of powdered sugar to the creamed butter. Beat on medium speed until the mixture is light, fluffy, and fully incorporated, approximately 3-5 minutes.

Incorporate the Egg: Crack in 1 large egg and mix on low speed until everything is well combined, which should take about 1-2 minutes.

Whisk the Dry Ingredients: In a separate bowl, sift together 3 cups of all-purpose flour, ½ cup of black cocoa powder, ½ cup of Dutch process cocoa powder, and ½ teaspoon of salt. Whisk gently until they blend perfectly.

Combine Wet and Dry Ingredients: Gradually add the dry mixture to the wet ingredients in the stand mixer. Mix on low speed just until the flour is incorporated, typically around 1-2 minutes.

Form the Dough: Turn the dough onto a clean surface and gently bring it together into a ball using your hands. Knead slightly for about 1 minute, then flatten it into a disc about 1-inch thick.

Chill the Dough: Wrap the dough tightly in cling wrap and place it in the refrigerator to chill for at least 30-45 minutes.

Roll Out the Dough: After chilling, roll out the dough between two sheets of parchment paper until it's about 4 mm thick.

Cut and Chill Shapes: Use your favorite cookie cutters to cut out spooky shapes from the rolled dough. Place them on a lined baking tray, then chill in the refrigerator for an hour or overnight.

Preheat the Oven: Preheat your oven to 160°C (320°F) as you wait.

Bake the Cookies: Once preheated, bake the cookies for about 10 minutes.

Cool and Decorate: Allow the cookies to cool on the baking sheet for 5 minutes, then transfer them to a cooling rack to cool completely.