In a food processor, blend flour, salt, and butter until it's crumbly. Add cold water gradually until the dough starts coming together. It should be crumbly but easily form into a ball when pinched.

Place the mix on a surface, gently form it into a ball, and roll it into an 8x12” rectangle. Cover and freeze for 20 minutes.

While that's chilling, shred the remaining butter and freeze for 15 minutes.

Spread half of the shredded butter on 2/3 of the pastry sheet. Fold the bottom third up and the top third down. Freeze for 15 minutes.

Rotate 90 degrees, roll into an 8x12” sheet, and repeat with the remaining butter. Freeze for 10 minutes.

Roll out into a large rectangle, do a double turn (in fourths). Rotate 90 degrees, roll out again, and make a single turn (in thirds).

Refrigerate for 20 minutes, then roll into a 12x24” sheet. Divide into 2 halves, cover, and store in the fridge or freezer.

Mix sugar and salt. Spread half onto 1 puff pastry sheet. Fold it into thirds, rotate 90 degrees, and roll out into a 5x20” rectangle.

Sprinkle the other half of the sugar mix and press gently. Fold each edge inwards so they meet in the middle. Repeat once more. Flatten with a rolling pin, then fold into half to create the palmier shape.

Place in the fridge for 20 minutes and preheat your oven to 400°F.

Cut the pastry into 10 palmiers along the length, each about 1/2” wide. Place them on a lined baking sheet and brush with the egg wash.

Bake for 20 minutes, flipping upside down halfway.

Enjoy your homemade Palmiers!