Preheat your oven to 350°F (175°C).
Line two baking sheets with parchment paper.
Chop pistachios in a food processor.
Set everything aside and get ready.
Beat softened butter with both sugars.
Mix until light and fluffy (about 2 minutes).
Add the egg and vanilla extract.
Beat until well combined and smooth.
Mix flour, baking soda, and salt together.
Add this to the butter mixture slowly.
Stir just until everything comes together.
Don't overmix the dough!
Fold in the chopped pistachios gently.
Make sure they're evenly distributed throughout.
The dough should be thick and sticky.
Scoop dough into balls (about 2 tablespoons each).
Place them on prepared baking sheets.
Leave 2 inches between each cookie.
Press a few pistachio pieces on top.
Bake for 10-12 minutes until edges are golden.
Centers will look slightly underdone - that's perfect!
Let cookies cool on the sheet for 5 minutes.
Transfer to a cooling rack carefully.
They'll firm up as they cool.
Enjoy warm or store in an airtight container!