Preheat the oven to 350°F (175°C).
Grease and flour two 9-inch round cake pans.
In a bowl, cream together the butter and sugar until light and fluffy.
Add the eggs one at a time, beating well after each addition.
Mix in the rosewater and milk, blending well after each addition.
In another bowl, combine the flour and baking powder, then gradually add to the wet mixture.
Gently fold in the pistachios to the batter until just combined.
Divide the batter evenly between the prepared cake pans and smooth the tops.
Bake in preheated oven for 25-30 minutes or until a toothpick inserted in the center comes out clean.
While the cakes bake, prepare the milk syrup by combining condensed milk with a bit of water in a saucepan over low heat.
Once the cakes have cooled for 10 minutes, remove them from the pans and place them on a wire rack.
Poke holes into the cooled cakes and drizzle the milk syrup over each layer evenly.
Stack the layers and top with additional pistachios and edible rose petals for garnish.
