Add the pistachios to a food processor with ¼ cup milk and the 1 tbsp of powdered sugar. Process on high for 5 minutes, until the pistachios turn into a smooth paste (scrape the sides along the way).

In a small saucepan over low heat, add the remaining milk (½ cup), white chocolate, and butter. Mix until the chocolate and butter are melted. Set aside and let cool slightly.

Then, pour the white chocolate mixture into the food processor with the pistachio paste. Process on high until extra smooth and creamy.

Set aside to use or store in an airtight container in the fridge for 2 weeks.

In a large bowl, whip the heavy cream until stiff peaks form. Then, add the cream cheese, powdered sugar, and ½ cup of the pistachio cream (you will use the rest to fill the croissant). Whip on high until well combined, thick, and creamy. Place into the fridge until ready to use.

Preheat the oven to 350F. Grease a 9” round (or 8” or 9” square) baking pan with cooking spray, then line with a sheet of parchment paper. Place onto a baking sheet; set aside.

Slice a croissant in half, and spread ~1 tbsp of the pistachio cream onto the croissant. Top with the other half, and then cut into 6 large cubes. Repeat the process until all of the croissants are done (you should have leftover pistachio cream).

Combine all of the ingredients for the custard, except for the eggs, in saucepan over medium-low heat. Whisk to combine until the butter is melted. Remove from heat and let cool slightly. Then, add the eggs and whisk until the eggs are fully incorporated.

Place ⅓ of the croissant cubes on the bottom of the prepared pan. Spread a little more of the pistachio cream on top, and then sprinkle with half of the chopped chocolate/chocolate chips. Repeat that process one more time. Then finish by topping with the last ⅓ of the croissant cubes.

Pour the custard all over and gently press down. Top with a sprinkle of turbinado sugar. Let sit for 15 minutes.

Bake at 350F for 35-45 minutes, until the top is golden and set, but the middle is still slightly wobbly when shaken. Remove and let rest for at least 10 minutes.

Serve warm with a scoop of the pistachio whipped cream.