In a large bowl, sift together flour, baking powder, baking soda, salt, and spices. Set aside.
In the bowl of an electric stand mixer fitted with the paddle attachment, cream together on medium speed butter and sugar until well combined, about 2 minutes. Add in fake egg, molasses, and vanilla; mix until combined. Gradually add the flour mixture on low speed, until combined.
Divide dough into two equal portions. Form each half into a round disk, and wrap in plastic. Chill in the refrigerator for at least 30 minutes, up to 4 days.
When you're ready to bake the cookies, preheat the oven to 350°F (180º C). Line a cookie sheet with parchment paper.
Roll each portion out, between two sheets of parchment paper, to 1/4 to 1/8-inch thickness. Use a cookie cutter to cut the dough into your desired shapes. Then transfer them to the prepared cookie sheet, spacing cookies about 1-inch apart.
Bake for 7 - 8 minutes, or until slightly set. Take them out of the oven. Let them sit for 2-3 minutes and then use a metal spatula to transfer cookies to a wire rack to cool completely.
Decorate as desired. Eggless Royal icing recipe here.