Combine the sugar, water, and lemon juice in a 1-quart saucepan over medium heat. Simmer for 8 minutes, stirring occasionally, until slightly syrupy and it coats the back of a spoon.

Remove from heat and stir in the rosewater and orange blossom water. Set aside to cool while you make the ashta.

Whisk the milk, heavy cream, cornstarch, and 2 tbsp sugar together in a 2-quart saucepan until no lumps remain.

Set over medium heat and cook, whisking constantly, for 8 to 10 minutes until the mixture thickens to a pudding-like consistency and coats the back of a spoon. Remove from heat and stir in the rosewater.

Pour into the 8x8-inch dish. Press plastic wrap directly onto the surface to stop a skin forming, then chill for at least 90 minutes until firm enough to spread.

Melt the butter in the 10-inch skillet over medium heat. Add the semolina and toast, stirring constantly, for 10 to 12 minutes until it turns golden and smells nutty. This is the step you can't walk away from, since semolina goes from golden to scorched in under a minute if the heat runs too high.

Reduce heat to low and pour in the cooled syrup in a slow stream, stirring constantly. The mixture will bubble and steam. Keep stirring for 3 to 5 minutes until the syrup is fully absorbed and the mixture pulls away from the sides of the pan in a thick, dough-like mass.

Transfer the semolina mixture to a serving platter and press into an even layer with the back of a spoon or an offset spatula. Let cool at room temperature for 30 minutes.

Once the semolina base is cool and the ashta is set, spread the chilled ashta evenly over the top.

Scatter the crushed pistachios over the cream and drizzle with the reserved syrup.

Slice into squares and serve at room temperature or chilled.