In a 2-quart/1.9L saucepan, combine the syrup sugar, water, and lemon juice. Bring to a simmer over medium heat and cook for 8 to 10 minutes, until slightly thickened. Remove from heat, stir in the rosewater and orange blossom water, and set aside to cool completely.

In a separate 2-quart/1.9L saucepan, whisk the milk, heavy cream, sugar, and cornstarch together while still cold. Set over medium heat and cook, whisking constantly, for 6 to 8 minutes, until the mixture thickens enough to coat the back of a spoon.

Remove the ashta from the heat and stir in the rosewater. Pour into a shallow bowl, press plastic wrap directly onto the surface, and cool to room temperature.

Heat the oven to 180C/350F. Brush a 23x33cm/9x13-inch baking pan generously with the tahini, coating the bottom and sides.

In a large mixing bowl, whisk the yogurt, sugar, and melted ghee together until smooth. Add the semolina, baking powder, and salt, and stir until you have a thick, spreadable batter. Let it rest for 10 minutes.

Spread half the batter into the prepared pan in an even layer. Spoon the cooled ashta cream over the top, spreading to within 1cm/0.5-inch of the edges. Cover with the remaining batter, smoothing the top so the cream is fully sealed in.

Score the top layer into diamonds or squares with a sharp knife, cutting only through the top layer of batter.

Bake for 35 to 40 minutes, until the top is deep golden brown and springs back when pressed.

Remove from the oven and immediately ladle the cooled syrup evenly over the hot cake. Let it sit for 10 to 15 minutes to soak in.

Re-cut along the score lines and scatter the crushed pistachios over the top.

Let the cake cool for at least 15 minutes before serving, or cool fully and serve at room temperature.