1. In a large bowl, whisk together the flour, baking soda, and salt. Set aside.
2. Using an electric mixer, beat the butter and sugar until smooth. (!!I don't have a mixer, so I guess it's super fork time.!!) Add the egg and beat until fluffy, about 2 minutes. Beat in the vanilla.
3. With the mixer on low, gradually add the flour mixture, mixing until just incorporated (the dough will be stiff). Shape into a disc and refrigerate, wrapped, for at least one hour and up to 3 days.
4. Roll out dough on a flat, floured surface. Use holiday cookie cutters to shape. Bake at 350°F on parchment-lined baking sheets, spacing the cookies at least 1½ inches apart until just beginning to brown (appx. 12-15 minutes). Transfer to wire racks to cool. Decorate with colored sugar and/or icing.