Preheat the oven to 180C/350F and grease and line an 11x7 inch pan.
Place sugar and butter into a large bowl, or the bowl of your stand mixer and beat until light and fluffy. About 2 minutes on medium-high speed.
Add in the egg and vanilla extract, scraping down the sides as necessary, then mix until well incorporated, about 1 minute.
Add in the pumpkin and then place the flour, cornflour, spices, bicarb, baking powder, salt and chocolate chips into a medium sized bowl and stir until the chocolate chips are coated in flour.
Tip the flour mixture into your egg mixture and mix on low until a soft dough forms.
Spoon just over ½ of the cookie mixture into your prepared pan and spread into an even layer.
Place in the oven for 10 minutes until slightly puffy, then remove from the oven and spoon the caramel all over the cookie dough.
Spoon the remaining cookie dough over the caramel layer.
Place in the oven for 15-20 minutes until the top is risen and golden and feel a little crunchy to the touch.
Leave to cool in the pan completely, before placing in the fridge until firm.
Transfer the Cookie Bars onto a cutting board and slice into 9-12 bars.
Best served at room temperature.
