📋 Instructions

1. 1Make the dough — Whisk 425 g flour with 6 g salt, then cut in 340 g cold butter until pieces are pea-sized. Add 120 g ice water one tablespoon at a time until the dough just holds together (overworking makes it tough).
2. 2Chill the dough — Flatten the dough into two discs, wrap, and refrigerate for 45 minutes. Cold butter is what creates the flaky layers during baking.
3. 3Cook the filling — Simmer 425 g pumpkin, 100 g brown sugar and 8 g spice in a saucepan over medium heat for 8 to 10 minutes. It is done when a spoon dragged across the pan leaves a clean track (the mixture should be thick, not runny).
4. 4Cool the filling — Spread the filling on a plate and cool for 15 minutes. Warm filling softens the butter in the dough and causes blowouts.
5. 5Roll and fill — Roll one disc into a 25 by 35 cm (10 by 14 inch) rectangle on floured paper. Spread the cooled filling, leaving a 2 cm (3/4 inch) border.
6. 6Top and seal — Roll the second disc to the same size and lay it over the filling. Press the border closed, then crimp with a fork (a double seal holds during the oven rise).
7. 7Chill and vent — Slide the slab onto a lined tray and chill for 20 minutes. Brush with beaten egg, sprinkle 20 g demerara sugar, and cut six 5 cm slits in the top.
8. 8Bake the slab — Bake at 200 C (400 F) for 28 to 32 minutes. It is done when the pastry is deep golden brown and the filling bubbles at the vents (an instant-read thermometer in the center reads 95 C / 203 F).
9. 9Ice and slice — Cool for 10 minutes, then whisk 120 g powdered sugar with 30 g maple syrup and 15 g milk and spread over the warm slab. Let it set for 10 minutes before cutting into six pieces.