Pithiviers’ beautifully scored surface is the first gift to behold. The second, as you bite in: both subtle and deeply flavorful, creamy chocolate-chestnut purée delights, framed by the flakiest crumb.
Thaw pastry overnight in refrigerator. In a small saucepan, combine chestnuts, milk, and sugar, and bring to a simmer. Over low heat, cook chestnuts until soft, about 20 minutes. Allow to cool slightly. Use an immersion blender and purée the chestnut mixture until smooth and thick. Set aside to cool completely. Transfer to a small bowl, fold chocolate pieces and honey into chestnut purée, cover, and chill. This can be done up to 3 days in advance. Between layers of lightly oured parchment, roll puff pastry to 1⁄8” thick. Use a 31⁄2” diameter cutter to pierce pastry rounds for 8–10 pithiviers, chilling pastry and rolling scraps as needed. Transfer rounds on parchment to a baking sheet and refrigerate. Make simple syrup glaze. In a small saucepan over medium heat, dissolve 2 tablespoons sugar in same amount of water, stirring as needed. Remove from heat, transfer to a small bowl, and cover. This can be done up to a week in advance. Measure tablespoons of chocolate- chestnut mixture and flatten into disks. Place onto pastry rounds, leaving a 1 cm border on all sides, and paint border with egg wash. Arrange pastry tops and press gently to seal. Chill pastry if it becomes smeary/ stretchy at any point. Pour a little egg wash and simple syrup into a small bowl and whisk to combine. Paint sweetened egg wash over filled pastries and chill for a half hour. Preheat oven to 400°F. Bring pastries from refrigerator, 1 at a time, and paint with sweetened egg wash again. Use a very sharp knife or razor to score each pastry surface with curved or geometric designs. Using the back of the knife, make indents to the pastry edge for a decorative finish. Freeze pastries for at least 15 minutes, up to 1 hour. Bake on 2 baking sheets, evenly spaced, for 20 minutes or until golden. Rotate pans and reduce temperature to 350°F and bake 20 minutes more, or until deeply golden. Transfer to a wire rack placed on top of parchment to cool, and immediately paint with simple syrup to achieve the glazed surface. Serve warm or room temperature.