Creating Buttery Pistachio Thumbprint Cookies is easy when you follow these steps:

1. Preheat Oven: Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper.
2. Cream Butter and Sugars: In a large bowl, cream together the softened butter, granulated sugar, and powdered sugar until light and fluffy.
3. Add Vanilla: Mix in the vanilla extract until well incorporated.
4. Combine Dry Ingredients: In a separate bowl, whisk together the flour and salt.
5. Mix Dry into Wet: Gradually add the dry ingredients to the butter mixture, mixing until just combined.
6. Incorporate Pistachios: Fold in the finely chopped pistachios, ensuring they are evenly distributed throughout the dough.
7. Shape the Cookies: Scoop out tablespoon-sized portions of dough and roll them into balls. Place them on the prepared baking sheet.
8. Make Thumbprints: Use your thumb or the back of a measuring spoon to create a small indention in the center of each cookie.
9. Fill with Jam: Spoon a small amount of fruit jam or chocolate spread into the indentation of each cookie.
10. Bake: Place the baking sheet in the preheated oven and bake for 20-25 minutes or until the edges turn lightly golden.
11. Cool: Remove from the oven and let the cookies cool on the baking sheet for about 10 minutes before transferring to a wire rack to cool completely.

These steps will guide you in creating these incredible cookies with ease!