Preheat your oven to 350°F (175°C). Line an 8x8-inch baking pan with parchment paper. Cream the butter and sugar together until light and fluffy. Add eggs one at a time, then mix in vanilla and rosewater.

In a separate bowl, whisk together flour, baking powder, salt, and ground pistachios. Gradually add the dry mixture to the wet ingredients, alternating with milk, until well combined.

Pour the batter into the prepared pan and spread evenly. Bake for 30 minutes or until a toothpick inserted in the center comes out clean. Let the cake cool completely on a wire rack before cutting.

Once cooled, trim the edges and cut the cake into 1-inch squares or use a small round cutter for uniform mini pastries. If desired, stack two layers with a thin spread of jam in between.

In a saucepan, combine powdered sugar, corn syrup, water, and vanilla extract. Warm over low heat while stirring until smooth. Add a few drops of pink food coloring if you want a soft blush hue.

Place the cake pieces on a wire rack over parchment paper. Spoon or pour the icing over each piece, ensuring an even coat. Let them set for 30 minutes.

Before the icing fully hardens, sprinkle with crushed pistachios and edible rose petals. Arrange them in mini dessert cups for a stunning presentation.