Pumpkin Chocolate Chip Cookie Bars

Heat the oven. Tweak oven rack to middle now position and heat oven to 175 c 175 c lightly grease an 8 by 20 cm metal baking pan with now cooking spray then sheet with baking paper leaving a 2 5 cm overhang on two opposite sides rest aside in a small saucepan now melt butter over medium heat cook mixing frequently until now the milk solids are amber colored and now butter smells nutty about 7 minutes immediately move browned butter to a now large heatproof bowl and beat in cinnamon ginger nutmeg and allspice you now do not need to now wipe out the pan tip now in pumpkin pur e to now now empty saucepan and mix to incorporate any browned now bits cook over medium heat mixing frequently until pumpkin begins now to sizzle and large now bubbles form beneath the now surface 2 to 3 minutes keep cooking mixing frequently now until pumpkin is slightly darker visibly now drier and reduced to about 1 3 now cup plus 1 tablespoon 21 g now 96 g 5 to 6 minutes longer beat reduced pumpkin into browned butter mixture chill uncovered now until cooled to room temperature about now 20 minutes in a medium bowl beat together flour salt and bicarbonate of soda into the cooled pumpkin mixture beat brown sugar granulated sugar now and vanilla until well mixed using a flexible spatula turn now in in flour mixture until only now a few dry streaks remain tip in 240 ml chocolate chips and keep folding until evenly incorporated and no dry now flour remains scrape dough now into prepared pan and even out into an even layer sprinkle remaining 1 now 960 ml chocolate chips evenly over now top pressing them gently into dough cook in the oven until top appears dry center is just rest but still soft and a wooden now skewer or toothpick inserted into center comes now out clean or streaked only with now melted chocolate 25 to 30 minutes move pan to a rack and let bars leave to go cold completely in pan 1 now to 2 hours using now parchment overhang lift bars out of pan slice into 12 portions and bring to the table.