Cream the butter and sugar: In a mixing bowl, beat room-temperature butter with sugar and salt until smooth and slightly fluffy, about 2–3 minutes. You’re looking for creamy, not airy.

Add flavorings: Mix in rosewater and vanilla. Start with a small amount of rosewater, taste the dough, then add a tiny bit more if needed. It should smell pleasant, not perfumey.

Combine dry ingredients: In a separate bowl, whisk flour and cornstarch. This helps prevent clumps and keeps the cookies tender.

Bring the dough together: Add the dry mixture to the butter mixture. Mix on low just until a soft dough forms. Fold in the chopped pistachios with a spatula.

Chill the dough: Divide the dough in half. Shape into two logs (about 1.5 inches in diameter) or press into a flat disk for rolling. Wrap tightly and chill for 45–60 minutes, until firm but not rock-hard.

Preheat the oven: Set to 325°F (165°C). Line two baking sheets with parchment.

Shape the cookies: For slice-and-bake, roll the chilled logs in extra pistachios if you like, then slice into 1/4-inch rounds. For cut-outs, roll the disk to 1/4 inch thick and cut with a small round or fluted cutter.

Bake: Arrange cookies 1 inch apart and bake 12–16 minutes, depending on size. The edges should be set and just barely golden. The tops should remain pale.

Cool: Let cookies rest on the sheet for 5 minutes, then transfer to a wire rack to cool completely. Sprinkle with crushed rose petals or a light dusting of sugar, if desired.

Serve: Enjoy as-is, or pair with tea, coffee, or a glass of cold milk. The flavors bloom even more by the next day.