Whisk together flour, salt and pumpkin spice.
Using an electric mixer beat the butter and sugar together until light and fluffy, about 5 minutes.
Add vanilla bean, mix well, then add the eggs. Beat to combine.
Add the flour mixture and mix until fully combined.
Separate the dough in 3 even pieces, wrap in plastic wrap and place in the fridge to chill for at least 30 minutes.
When ready to bake, preheat the oven to 350 degrees Fahrenheit. Line cookie sheets with parchment paper.
Lightly flour a work surface and roll the dough out to ¼ inch thickness.
Dust Shamrock cookie cutter with flour and cut into shapes.
For Stained glass look - cut dough with large circle cookie cutter (make sure Shamrock cookie cutter fits into circle). Then cut shamrock inside circle. Fill each Shamrock shape with crushed green lifesavers. Cookie sheet MUST be lined with parchment paper or cookies will stick to cookie sheet.
Bake for 8-10 minutes. The edges just starting to brown.
Cool completely on the cookie sheets.
Decorate with royal Icing.