Preheat oven to 350°F (175°C). Prepare two 9-inch round cake pans.

Make mango reduction by simmering mango puree until reduced by 1/4, then chill.

Whisk milk, egg whites, orange flower water, and vanilla extract.

Combine dry ingredients (flour, sugar, baking powder, salt, cardamom, saffron) in a mixer.

Add butter to dry ingredients and mix until crumbly.

Gradually add wet ingredients to the dry mixture and beat until smooth.

Divide batter evenly into the prepared pans.

Bake for 23-25 minutes, or until a toothpick comes out clean.

Cool cakes in pans for 5 minutes, then invert onto a cooling rack to cool completely.

Toast pistachios at 350°F (175°C) for 3-4 minutes. Crush and reserve some for garnish.

Make frosting by whisking egg whites and sugar over simmering water until frothy.

Transfer to a mixer and whip until thick and glossy.

Add butter gradually, then mango reduction, and beat until fully incorporated.

Level the tops of the cooled cakes.

Place one cake layer on a platter, spread with frosting and sprinkle with pistachios.

Top with the second cake layer, apply a crumb coat, and refrigerate.

Frost the cake smoothly and pipe stars around the border.

Sprinkle the reserved pistachios in the center of the cake.