Place the pistachios in the bowl of a food processor and grind until finely ground, stopping before it turns into butter. Set aside.

Combine butter and sugar in a bowl and beat with an electric mixer until creamy. Add almond extract and mix in well. Add 3 tablespoons ground pistachios, flour, and salt; mix until the dough comes together.

Place dough on a piece of plastic wrap that has been sprinkled with flour. Wrap up and place in the refrigerator for 1 hour.

Preheat the oven to 350 degrees F (175 degrees C). Line a baking sheet with parchment paper.

Combine egg and water in a bowl and beat with a fork. Place remaining ground pistachios in a separate bowl. Shape the dough into 12 equal balls. Roll in the beaten egg and then in the ground pistachios. Set balls 2 inches apart onto the prepared baking sheet.

Make an indentation in the middle of each ball with your thumb or the handle of a wooden spoon. Place 5 to 6 baking chips in each indentation.