In a stand mixer fitted with the paddle attachment, beat the butter and both sugars until fluffy. (Alternatively, use a large bowl and a handheld electric mixer).
Beat in the molasses, egg and vanilla.
In a separate bowl, combine the flour, salt, baking soda and spices.
With the mixer running on low speed, slowly add the flour mixture into the butter mixture until fully incorporated.
Form the dough into a disc. Wrap in plastic wrap and refrigerate at least 30 minutes.
When ready to bake, preheat oven to 350 degrees. Line baking sheets with parchment paper. Roll the dough out onto a lightly floured surface and use cookie cutters to cut into desired shapes. Place the cookies onto the prepared baking sheets.
Bake 10-12 minutes. For best results, cool completely on a wire rack before decorating.
To make the frosting, beat the butter and sugar until fluffy. Add the milk, one tablespoon at a time, until desired consistency is reached. Beat in the vanilla bean paste. (If using a real vanilla bean, slice the pod open lengthwise and scrape the insides into the mixing bowl. Beat to incorporate.)