Combine Dry Ingredients: In a medium bowl, whisk together the plain flour, bicarbonate of soda, salt, and all the ground spices (cinnamon, ginger, nutmeg). Set aside.

Cream Butter and Sugars: In the bowl of a stand mixer fitted with the paddle attachment, or in a large bowl with a hand mixer, beat the softened unsalted butter with the light brown sugar and caster sugar on medium-high speed for 2-3 minutes until the mixture is light, pale, and fluffy. For a detailed guide on this technique, BBC Good Food has a great explanation on how to cream butter and sugar correctly.

Add Wet Ingredients: Add the egg and vanilla extract and beat again until well combined, scraping down the sides of the bowl as needed.

Add the Pumpkin: Add the blotted pumpkin puree and mix on a low speed until just incorporated. Don't overmix here. I find that mixing on low prevents the pumpkin from splashing out of the bowl.

Combine Wet and Dry: With the mixer on its lowest speed, gradually add the dry flour mixture to the wet ingredients in three additions, mixing until just combined after each one. Be careful not to overmix the dough.

Chill the Dough: Cover the bowl with cling film and refrigerate the dough for at least 30 minutes, or up to an hour. This step is essential to prevent the cookies from spreading too much in the oven.

Prepare for Baking: When you're ready to bake, preheat your oven to 180°C (160°C fan) and line two large baking trays with parchment paper. In a small, shallow bowl, mix together the 100g of caster sugar and 2 tsp of ground cinnamon for the topping.

Shape and Coat: Remove the chilled dough from the fridge. Using a medium cookie scoop or a tablespoon, scoop out portions of dough (about 2 tablespoons each) and roll them into smooth balls between your hands. Roll each ball generously in the cinnamon-sugar mixture until it's fully coated.

Bake the Cookies: Place the sugar-coated dough balls on the prepared baking trays, leaving about 5cm (2 inches) of space between them to allow for spreading. Bake for 12-15 minutes, or until the edges are set and lightly golden. The centres will still look soft and slightly puffy.

Cool Down: Let the cookies cool on the baking trays for 5 minutes. This allows them to set up properly. Then, carefully transfer them to a wire rack to cool completely.