Whisk the flour, cocoa powder, baking powder, and salt together in a medium bowl. Set aside.

In a large bowl using a hand mixer or a stand mixer fitted with a paddle attachment, beat the butter and sugar together on high speed until completely smooth and creamy, about 3 minutes. (Here’s a helpful tutorial if you need guidance on how to cream butter and sugar.) Add the egg and vanilla and beat on high speed until combined, about 1 minute. Scrape down the sides and up the bottom of the bowl and beat again as needed to combine.

Add the dry ingredients to the wet ingredients and mix on low until combined. Dough will be soft. If the dough seems too soft and sticky for rolling, add 1 more Tablespoon of flour.

Divide the dough into 2 equal parts. Dust 2 large pieces of parchment paper or 2 silicone baking mats with cocoa powder (or flour). Place a dough half on each. With a rolling pin lightly dusted with cocoa powder (or flour), roll the dough out to about 1/4-inch thickness. Use more cocoa powder/flour if the dough seems too sticky. The rolled-out dough can be any shape, as long as it is evenly 1/4-inch thick.

Lightly dust one of the rolled-out doughs with cocoa powder or flour. Place a piece of parchment on top. (This prevents sticking.) Place the 2nd rolled-out dough on top. Cover with plastic wrap or aluminum foil, then refrigerate for at least 1-2 hours and up to 2 days.

Once chilled, preheat oven to 350°F (177°C). Line 2-3 large baking sheets with parchment paper or silicone baking mats. Carefully remove the top dough piece from the refrigerator. Using cookie cutters (here is a 5-piece Halloween set that includes many of the shapes you see in these photos), cut the dough into shapes. Re-roll the remaining dough, using more cocoa powder or flour to lightly dust your work surface and rolling pin, and continue cutting the dough until all is used. Work quickly so the dough doesn’t become too warm or soft. If it does, stop what you’re doing and place any unused dough back in the refrigerator for 10 minutes to stiffen up again. Repeat cutting into shapes with 2nd half of dough. (Note: It doesn’t seem like a lot of dough, but you get a lot of cookies from the dough scraps you re-roll.)

Arrange shaped cookies on baking sheets 3 inches apart. Bake for 11-12 minutes or until edges are set. If your oven has hot spots, rotate the baking sheet halfway through bake time. Allow cookies to cool on the baking sheet for 5 minutes and then transfer to a wire rack to cool completely before decorating.

Prepare the royal icing or easy cookie icing. Divide the icing into separate bowls if you wish to tint it different colors using gel food coloring. I divided the icing into 4 equal portions, left 1 portion white, and tinted the other portions of icing orange, black, and green. When tinting icing, only use 1-2 drops at first, stir it in, then add more as needed to reach your desired color. I usually need quite a few drops to make black icing. (Remember, color darkens as icing dries.)

Read this step completely before starting and see recipe notes for recommended decorating tools. Spoon icing into piping bags fitted with Wilton Piping Tip #4. If you kept the icing white or are only using 1 color of icing, you just need 1 piping bag. Slowly pipe icing border around the cookies, and then fill the center with more icing. Keep the icing a thin layer so it dries faster. You can also decorate the cookies how I do in the video tutorial, including sprinkle stripes on the witch hats and sprinkle body on the bat. (These looks work with royal icing or the easy glaze icing.) No need to let the sprinkle stripes/sprinkle body dry before piping icing on the other parts of the cookie. You also do not have to wait for the orange icing to dry before piping the green stem on the pumpkin. If piping green leaves and a face on the pumpkin to make a Jack-O-Lantern, use royal icing and make sure the orange icing sets before adding these additional layers. (Royal icing is best for fine detail/layers.) I did quite a few royal icing Jack-O-Lantern looks in the picture above and the easiest is slanted semi-circles for eyes, triangle nose, and a curved zig-zag smile. If you ever need to thicken royal icing because it has thinned out while you’re decorating or you want thicker icing for piping fine detail, you can beat 2-3 extra Tablespoons of confectioners’ sugar into it to help it thicken up. If adding eyeballs to the cookies, pipe a tiny dot of icing on the back of the eyeball before gently pressing onto the iced cookie. As always, take your time icing the cookies and know that each and every one won’t be perfect.

Royal icing dries in about 2 hours and easy glaze icing dries in 24 hours. No need to cover the decorated cookies as you wait for the icing to set. If it’s helpful, transfer cookies to a baking sheet and place them in the refrigerator to help slightly speed up the icing setting.

Enjoy cookies right away or wait until the icing sets to serve them. Once the icing has set, these cookies are great for gifting or for sending. Plain or decorated cookies stay soft for about 5 days when covered tightly at room temperature. For longer storage, cover and refrigerate for up to 10 days.