Reduce the oven temperature to 175 C [350 F ] and line the muffin tin with muffin liners, or lightly grease and flour the tin.
Gather and weigh your ingredients
In a large mixing bowl, sift together the flour, bicarbonate, baking powder and spices.
In a separate bowl, beat the eggs, sugar and oil until blended then add the sugar, salt and pumpkin puree.
Fold the pumpkin mixture into dry ingredients, and add the walnuts until just mixed.
Using a piping bag fitted with a large nozzle [to allow for the crushed walnuts] pipe the mixture into the prepared muffin tin to just about to the top of the muffin case for a real nice risen muffin top. [note if you fill this too much, it will rise over the top and and bake onto the actual muffin tin]If you are using a spoon to fill the prepared tin, go gently as it can get a bit messy. Check on the muffins after about 12-15 minutes for the mini muffins and 20-25 minutes for the large muffins. They should be golden, risen and when a toothpick inserted into the centre of the muffin comes out clean.
Remove from the oven and place the muffins in the tin on a cooling rack for about 5 minutes, or until the muffins can be handled. Remove the muffins in their cases and continue to cool on the rack. Serve immediately, or store in an airtight container once the muffins have completely cooled to avoid any condensation build up in the inside of the container.
Enjoy!