Preheat your oven to 350°F (175°C). Lightly grease an 8-inch round cake pan with butter or oil, then dust it with flour to prevent sticking.

In a medium bowl, whisk together the all-purpose flour, finely ground pistachios, baking powder, baking soda, and salt.

In a large mixing bowl, beat softened unsalted butter and granulated sugar together on medium speed for about 3-4 minutes until light and fluffy.

Add the large eggs to the butter-sugar mixture one at a time, mixing well after each addition. Stir in the pure vanilla extract and rosewater until fully combined.

Gradually add the dry ingredient mixture to the wet mixture, alternating with room temperature whole milk. Start and end with dry ingredients.

Pour the batter into your prepared cake pan and spread it evenly. Bake for 25-30 minutes until a toothpick inserted comes out clean.

Once baked, cool the cake in the pan for about 10 minutes before transferring it to a wire rack to cool completely.

Slice the cooled cake into wedges and serve each piece with a generous dollop of fresh whipped cream and a sprinkle of chopped pistachios.