Making the Top Crust:

1. Follow the same steps for making the crust dough as for the base. Instead of pressing the dough into the pan, roll it out to about 1/4 inch thickness between two sheets of parchment paper.
2. Place the rolled-out dough on a baking sheet and remove the top layer of parchment paper.
3. Bake in the preheated oven at 350°F (175°C) for 20-25 minutes or until golden brown and crisp. Let it cool completely before crumbling it or processing it into coarse crumbs.

Assembling the Cannoli Squares with the Top Crust:

1. After spreading the ricotta filling over the cooled base and setting it in the refrigerator, sprinkle the crumbled top crust over the filling. Gently press the crumbs into the filling to help them adhere.
2. Continue chilling the squares, dust them with powdered sugar, and garnish with mini chocolate chips and chopped pistachios.

Make the Crust:

1. Preheat the oven to 350°F (175°C). Line a 9×9-inch baking pan with parchment paper, leaving overhang on the sides for easy removal.
2. In a large bowl, whisk together the flour, sugar, and baking powder. Cut in the cold butter until the mixture resembles coarse crumbs.
3. Add the egg and vanilla extract, mixing until the dough comes together. Press the dough evenly into the bottom of the prepared pan.
4. Bake the crust for 15-18 minutes, or until lightly golden. Let it cool completely.

Prepare the Filling:

1. In a medium bowl, combine the ricotta cheese, powdered sugar, vanilla extract, and orange zest (if using). Mix until smooth and creamy.
2. Fold in the mini chocolate chips.
3. Spread the ricotta filling over the cooled crust, smoothing the top with a spatula. Refrigerate for at least 2 hours, or until the filling is set.

Garnish and Serve:

1. Once chilled, lift the dessert from the pan using the parchment paper overhang and transfer it to a cutting board.
2. Cut into 12 squares and dust with powdered sugar. Top with mini chocolate chips and chopped pistachios for added crunch and color.