Preheat your oven to 375°F (190°C) and generously butter a 9x13-inch baking dish or a round 12-inch cake pan.

Prepare the simple syrup by combining 1 cup of water, 1.5 cups of sugar, and lemon juice in a medium saucepan over medium-high heat. Bring to a boil, then reduce the heat and simmer for 10 minutes until slightly thickened. Remove from heat, stir in the rose water, and let it cool completely.

In a large mixing bowl, pull apart the thawed kataifi pastry with your fingers to separate the strands, breaking them into smaller 1-inch pieces. Pour the melted butter over the pastry and toss thoroughly until every strand is evenly coated.

Press exactly half of the buttered kataifi mixture firmly into the bottom of the prepared baking dish to form an even, compact crust.

In a separate bowl, mix the ricotta cheese, shredded mozzarella, and 1/4 cup of sugar until well combined. Spread this cheese mixture evenly over the bottom crust, leaving a 1/2-inch border around the edges to prevent burning.

Top the cheese layer with the remaining kataifi pastry, pressing down gently to cover the cheese completely and seal the edges.

Bake in the preheated oven for 35 to 40 minutes, or until the top and edges are a deep golden brown and the cheese is melted and bubbling.

Remove the knafeh from the oven and immediately pour the cooled rose water syrup evenly over the hot pastry. Garnish with chopped pistachios and serve immediately while the cheese is warm and stretchy.