Preheat your oven to 180°C (350°F) and line baking sheets with parchment paper.
In a large mixing bowl, combine softened butter and granulated sugar. Beat with a hand or stand mixer until the mixture is light, fluffy, and pale, filling your kitchen with a sweet, creamy aroma.
Add the egg and vanilla extract to the butter mixture. Mix until well incorporated and smooth, with a slight sheen.
Gradually add the sifted flour and baking soda to the wet ingredients. Mix on low speed until just combined; the dough should come together and be soft but manageable.
Lightly flour your work surface and roll out the dough to about 0.5 cm thickness. Keep the dough cool and firm for easier handling.
Use Halloween-shaped cookie cutters to cut out fun shapes from the dough. Gather the scraps, re-roll, and cut until all dough is used.
Transfer the cut-out cookies to the prepared baking sheets, spacing them evenly to allow for expansion.
Bake the cookies in the preheated oven for 8-10 minutes, or until the edges turn a light golden brown and the cookies feel firm to the touch.
Remove the cookies from the oven and let them cool on the baking sheet for a few minutes before transferring to cooling racks. Allow them to cool completely.
Once cooled, decorate the cookies with vibrant icing, edible paints, or other fun toppings to bring your spooky creations to life.
Enjoy your colorful, crispy-edged, chewy-centered Halloween sugar cookies with friends and family for a festive treat.