In a stand mixer, beat the butter and both sugars until fluffy.
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 and refrigerate at least 30 minutes.
When ready to bake, preheat oven to 350 degrees. Roll the dough out onto a floured surface and cut into desired shapes. Place the cookies onto a parchment-lined baking sheet. Bake 10-12 minutes. Cool completely 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.)