Preheat the oven to 350°F (175°C).

In a bowl, whisk together the flour, ground pistachios, baking powder, and salt.

In a separate bowl, cream the softened butter and granulated sugar until light and fluffy.

Add eggs, one at a time, mixing well after each addition, then stir in vanilla extract and rosewater.

Gradually add the dry ingredients to the wet mixture, mixing until just combined.

Divide the batter evenly into three greased 9-inch round cake pans.

Bake for 25-30 minutes or until a toothpick inserted in the center comes out clean.

While the cakes are baking, prepare the honey syrup by combining sugar, water, honey, and lemon juice in a saucepan over medium heat. Stir until sugar dissolves, then add rosewater and remove from heat.

Once the cakes are done, let them cool for 10 minutes before removing from pans.

Poke holes in the cakes and drizzle with honey syrup.

For the filling, whip the heavy cream until stiff peaks form, then fold in ricotta cheese and powdered sugar until smooth. Stir in ground pistachios.

Layer the cakes with the filling, spreading it evenly between each layer. Top with remaining filling and garnish with chopped pistachios and edible rose petals.