Preheat the oven to 180C/350F and line a 12 hole muffin tin with liners. Alternatively you can spray your muffin tin with cooking spray and bake the muffins directly in the pan.
Place the flour, baking powder, bicarbonate of soda, salt, spices, sugar and milk chocolate chips into a large bowl and stir briefly to combine. Make sure all the chocolate chips are coated in flour.
Add in the melted butter and eggs and mix until combined. Add in the pumpkin puree and continue to mix by hand until the batter has come together and there are no lumps of flour. The batter will be very thick.
Divide the batter between the muffin liners. Fill them level - I used a heaping 2tbsp cookie scoop to ensure even muffins.
Place in the oven for 15-20 minutes, until risen and an inserted skewer into the centre comes out clean.
Leave to cool for at least 15 minutes before digging in. These muffins are especially good when warm as the chocolate chips are melty. You can also serve them at room temperature.
Chocolate Pumpkin Muffins will keep in an airtight container, at room temperature for 5 days. As with most spiced things, they will taste more intensely spiced on the second day.
Note: I drizzled more melted chocolate onto my muffins - this is totally optional. I just melted some chocolate in a bowl, tipped it into a small Ziploc bag and then snipped a tiny bit of the corner of the bag off to drizzle it over each muffin.