In a large bowl using a stand mixer fitted with a paddle attachment, beat the butter and the brown sugar for 3 minutes on medium high speed. Add the molasses and beat on medium high speed until combined and creamy-looking.
10 Tablespoons Unsalted Butter, 3/4 Cup Light Brown Sugar, 2/3 Cup Molasses*
Scrape down the sides and bottom of the bowl.
Next, beat in egg and vanilla. Scrape down the sides of the bowl.
1 Large Egg, 3/4 teaspoon Vanilla Extract
Add the dry ingredients to the bowl. On low speed, slowly mix into the wet ingredients until combined.
Divide the cookie dough in half and place each onto a large piece of plastic wrap. Wrap each dough up tightly and pat down to create a flat disc shape.
Chill the discs for at least 3 hours and up to 3 days in the refrigerator. Chilling is mandatory for gingerbread cookie dough.
Remove 1 disc of chilled cookie dough from the refrigerator.
Generously sprinkle a work surface, as well as your hands and the rolling pin with powdered sugar, not flour.
Roll out disc until 1/4-1/2"-inch thick. Cut into shapes. Place shapes 1 inch apart on prepared baking sheets. Re-roll dough scraps until all the dough is shaped. Repeat with remaining disc of dough.
Bake cookies for about 9-10 minutes.
Allow cookies to cool for 5 minutes on the cookie sheet. Transfer to cooling rack to cool completely. Once completely cool, decorate with royal icing!
Royal Icing
In a large bowl, mix together the powdered sugar, water, vanilla and corn syrup until smooth. When you lift your spoon you should see the icing ribbon down onto the remaining icing, staying in its ribbon for a few seconds before melting back into the rest. If it doesn't hold it's shape just add a little more powdered sugar. If it's incredibly thick and doesn't melt back within a few seconds add a little more water.