For the Pistachio Croquant: In a medium saucepan over high heat, combine sugar and 300 grams water. Gently stir until sugar dissolves. Continue to cook over high heat for 10 to 15 minutes. Remove from heat and stir in pistachios. Pour pistachio mixture over sheet tray lined with parchment. Once cool, transfer to a food processor and grind until crumbled.

For the Craquelin Crust: In a large mixing bowl, combine all ingredients and 120 grams Pistachio Croquant using a spatula. Place dough between 2 sheets of wax paper and roll out to 1-millimeter thickness. Set aside.

For the Choux Pastry: To a medium saucepan over medium heat, combine cream, milk, 800 grams water, sugar, salt, and butter. Stir to melt butter then bring the mixture to a simmer. Remove from heat and sift in flour; stir to incorporate, forming a thick dough. Return to heat; continue to mix and move the dough for 1 to 3 minutes, until dough pulls away from the sides of the pan. Transfer to the bowl of a stand mixer fitted with a paddle; cool. Mix dough on low speed while slowly adding eggs. Keep mixing until dough is shiny, thick and smooth. Preheat oven to 450℉. Prepare a parchment-lined baking sheet; lightly spray with water. Transfer choux dough to a piping bag fitted with an 807 tip. To the baking sheet, pipe out medium-sized rings of choux, at least 3 inches apart. Using cookie cutters, punch out rings of Craquelin Crust so that they are about the same size as the choux. Top each choux ring with a Craquelin Crust ring, lightly pushing the crusts down to secure them. Transfer choux rings to the oven and reduce oven temperature to 350℉. Bake 30 minutes or until pastry has risen and top has browned without opening the oven door. Cool and set aside.

For the Pistachio Cream: In a saucepan, heat sugar and 667 grams water to 121℃. To a large bowl, add egg yolks and whisk, streaming in the hot sugar liquid until the bowl is cool to the touch. Stir in butter, pistachio paste and salt. Reserve.

For the Pistachio Praline: In a saucepan, heat sugar and 170 grams water to 165℃, stirring until a caramel forms. Pour caramel over pistachios; cool. Grind until it forms a paste consistency. Add pistachio paste until a nutty green color is reached. Season with salt.

To Assemble and Serve: Cut Choux Pastry in half lengthwise. On the bottom half, pipe Pistachio Praline. Layer with Pistachio Croquant, pipe a ring of Pistachio Cream. Sandwich with top half of Choux and top with more Pistachio Praline, powdered sugar and chopped pistachios. Cover Pistachio Cream with more chopped pistachios and serve.