Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans to prevent sticking.

Cream together the softened butter and granulated sugar until light and fluffy, about 3–4 minutes.

Incorporate the eggs one at a time, mixing well after each addition. Stir in the vanilla extract and rose water.

Whisk together the flour, baking powder, baking soda, salt, and ground pistachios in a separate bowl.

Combine the wet and dry mixtures by gradually adding the dry ingredients to the wet mixture, alternating with the milk.

Divide the batter evenly between the prepared cake pans and smooth the tops.

Bake for 30–35 minutes, or until a toothpick comes out clean. Allow the cakes to cool in the pans for about 10 minutes.

Beat the softened butter in a large bowl until creamy. Gradually add the powdered sugar, then add the heavy cream, vanilla extract, and rose water, and beat until smooth.

Layer one of the cooled cakes on a serving plate and spread a layer of frosting on top.

Stack the second layer of cake on top and generously frost the top and sides with the remaining frosting.

Decorate the top of the cake with chopped pistachios and additional rose petals if desired.

Slice and serve the cake chilled or at room temperature.