In a small saucepan, cook the pumpkin puree over medium-high heat with constant stirring, until you've reduced its weight to 75g (or its volume to about 1/3 cup). This should take about 5 minutes.

Set aside to cool until warm or room temperature.

Using a stand mixer with a paddle attachment or a hand mixer with the double beaters attachment (or by hand using a balloon whisk), cream the butter and both sugars together until pale and fluffy.

Add the reduced and cooled pumpkin puree, egg yolk and vanilla bean paste, and mix until fully incorporated.

Sift together the gluten free flour blend, baking powder, baking soda, xanthan gum, salt and spices. Add the dry ingredients to the wet and mix well until you get a smooth cookie dough. The cookie dough will be very soft and sticky at this point.

Stir in most of the chocolate of choice, reserving a handful for later.

Chill the dough in the fridge for at least 3 hours (in a bowl covered tightly with cling film) until firmed up and easily scoopable.

Using a "2 tablespoon" ice cream or cookie scoop, scoop individual portions of cookie dough. This recipe makes 13 cookies in total.

Place the cookie dough scoops snugly next to each other onto a baking sheet lined with baking/greaseproof paper, cover tightly with cling film and chill in the fridge for a further 30 minutes.

While the cookie dough is chilling for the second time, adjust the oven rack to the middle position, pre-heat the oven to 350ºF (180ºC) and line a separate baking sheet with baking/greaseproof paper.

Arrange the chilled cookie dough balls on the lined baking sheet so that they have enough space (about 2 inches/5 cm) around them for spreading out during baking – I usually bake 6 cookies at a time.

Tip: Top each cookie dough ball with a few pieces of chopped chocolate before baking. This will give the baked cookies those gorgeous, glossy puddles of chocolate once baked.

Bake the cookies at 350ºF (180ºC) for 14 – 16 minutes, depending on your preferred cookie texture and consistency. They should be golden brown around the edges when done.

At the 8 - 9 minute mark, take the baking sheet out of the oven, tap/bang it 5 – 7 times onto the kitchen counter, and then return to the oven. (Tapping the cookie sheet on the kitchen counter helps the cookies to flatten, thus giving them their characteristic shape and appearance. Omit the tapping if you want slightly thicker cookies.)

Return the cookies to the oven and bake until done. You can repeat the tapping/banging step once or twice more until the cookies are done.

Immediately out of the oven, you can correct the shape of the cookies into a more evenly round one. To do this, use a round cookie cutter slightly larger than the cookie diameter to nudge the cookies into shape.

Allow the cookies to cool on the baking sheet for 2 – 3 minutes, then transfer to a cooling rack to cool completely.

Storage:

The pumpkin chocolate chip cookies keep well for about one week in a closed container in a cool dry place.

You can also store the raw/unbaked cookie dough balls in an airtight container in the fridge for up to 1 week, or in the freezer for up to 1 month. You can then bake the cookies directly out the fridge/freezer (no need to thaw them), but you'll need to prolong the baking time by about 3 - 4 minutes.