1. Preheat oven to 350°F (175°C). Grease or line a 9×13-inch baking pan with parchment paper.

2. In a large bowl, cream together softened butter and granulated sugar until light and fluffy.

3. Add eggs one at a time, mixing well after each. Stir in vanilla extract.

4. Mix in the dry instant pistachio pudding mix until fully incorporated.

5. In a separate bowl, whisk together flour and baking powder. Gradually add to wet mixture until a soft dough forms.

6. Spread dough evenly into the prepared pan and press flat.

7. Bake for 22–26 minutes, or until edges are golden and center is set. Let cool completely.

8. In a small bowl, whisk together powdered sugar and milk to make a glaze.

9. Once bars are cool, spread glaze evenly over top.

10. Sprinkle crushed pistachios over glaze. Chill for cleaner slicing if desired, then cut into bars and serve.