Creating Buttery Pistachio Thumbprint Cookies can be a delightful process if you follow these simple steps:

1. Preheat Oven: Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
2. Cream Butter and Sugars: In a large mixing 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 combined.
4. Combine Dry Ingredients: In another bowl, whisk together the all-purpose flour, ground pistachios, and salt.
5. Mix Together: Gradually add the dry mixture to the wet mixture, stirring until just combined. Do not overmix.
6. Shape Cookies: Scoop tablespoon-sized portions of dough and roll them into balls. Place them on the prepared baking sheet, spacing them about 2 inches apart.
7. Create Thumbprint: Use your thumb or the back of a spoon to make an indentation in the center of each cookie.
8. Fill Indentations: Spoon your chosen jam or chocolate into the center of each thumbprint.
9. Bake: Place the baking sheet in the preheated oven and bake for 12-15 minutes, or until the edges are lightly golden.
10. Cool: Remove from the oven and let the cookies cool on the baking sheet for about 10 minutes. Then transfer them to a wire rack to cool completely.
11. Garnish (Optional): If desired, press a whole pistachio into the center of each cookie after filling for added decoration.

These steps will guide you in creating these incredible cookies effortlessly!