Preheat the oven to 325°F (163°C). Line a baking sheet with parchment paper.
Slice the vanilla bean pod lengthwise and scrape out the seeds using the back of a knife.
In a large mixing bowl, cream the softened unsalted butter and sifted powdered sugar together until light and fluffy, about 3 to 5 minutes.
Add the vanilla bean seeds to the butter and sugar mixture and mix until evenly incorporated.
In a separate bowl, whisk together the all-purpose flour and salt.
Gradually add the flour mixture to the butter mixture, mixing on low speed or folding gently with a spatula until a soft dough forms. Do not overmix.
Turn the dough out onto a lightly floured surface and shape it into a flat disk. Wrap the disk in plastic wrap and refrigerate for 30 minutes to firm up.
Remove the dough from the refrigerator and roll it out to about 1/4-inch thickness.
Use a cookie cutter or knife to cut the dough into desired shapes (such as rounds or rectangles). Place the cookies on the prepared baking sheet about 1 inch apart.
Bake in the preheated oven for 18 to 20 minutes, or until the edges are lightly golden but the centers remain pale.
Remove from the oven and allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.