Sometimes called galette du roi, this round puff pastry cake is sometimes fitted with a gilded paper crown meant to be worn by whoever bites into the “feve,” a bean meant to bring good luck, embedded in the galette. This cake is also a good vehicle for showing off your puff pastry since the rise can be dramatic.
Preheat the oven to 425°F. Cut the pastry dough in half. On a floured work surface, roll out each half into a square slightly larger than 10inches and slightly thicker than ⅛inch. Transfer one half to a sheet pan sprinkled with cold water. Using a 10-inch pie pan, tart ring, or similar template, cut out a 10-inch round.
Dollop the frangipane on the center of the round. Then, using a spatula, smooth it out into an even layer, leaving a 2-inch border uncovered. Brush the uncovered border with water. Loosely roll the remaining pastry around the rolling pin, and unroll it over the bottom round, covering the filling. Use a bowl or something the same diameter as the round on the bottom to cut the top round where it comes to the edge of the bottom round. Trim the edges as needed create an even round. Press around the edges to create a seal. Brush the top with the egg wash. Use a paring knife to create spokes that arc from the center to the outside edge.
Bake for about 25 minutes, or until well puffed and golden brown. Turn down the oven to 300°F and bake for 20 to 30 minutes longer, or as long as possible without overbrowning the pastry. The second half of the baking is to cook any raw dough left on the inside of the pastry. Let cool on a rack.
How to Make Pithiviers
Roll out a sheet of puff pastry and use a pie pan or other template to cut out a large disk.
Spread frangipane over the center, leaving a 2-inch border. Brush the border with water.
Unroll another sheet of puff pastry and place it over the bottom round to cover the filling.
Use a bowl that matches the diameter of the galette to trim away the excess pastry and create an even round. Press around the edges to seal.
Brush the top with egg wash, and make a series of spokes, starting from the center and working toward the outside.
Bake until well puffed and golden brown. Turn down the oven and bake as long as possible without overbrowning to cook the dough through on the inside. Serve in wedges.