Preheat the oven to 180°C. Line two standard 12-cup muffin tins with paper liners or grease with nonstick cooking spray. Set aside
Chop the walnuts and set aside. Now chop the dates. Roughly chop/ halve or quarter ⅔ of the dates and finely chop the other ⅓. Place the ⅓ finely chopped dates in a bowl with the 2 Tbsp (⅛ cup) flour, mix through and set aside**
In a small saucepan on the stove, combine the roughly chopped ⅔ dates, milk, baking soda and vanilla extract. Heat gently and let simmer for around 5 - 10 minutes until the dates soften
Once the dates have softened, use a hand/stick blender (or a normal blender) to blend the date and milk mixture until the dates are pureed (it does not have to be super smooth). Set aside to cool slightly
In the meantime, place the chopped ⅔ cup walnuts on a baking sheet and roast in the oven for around 5 minutes. Set aside to cool
In a medium bowl cream together brown sugar and butter using a hand mixer until smooth (or use your stand mixer). Add eggs and mix well
Add the slightly cooled milk and date mixture while whisking or stirring until combined
Then sieve in the 1 Cup flour, baking powder and salt and begin mixing through. Just before all the flour is incorporated into the wet ingredients, add the roasted walnuts and the left over date and flour mixture. Take care not to over-mix
Fill the prepared muffin tins evenly, about two-thirds of the way full. Sprinkle with the chopped un-roasted ⅓ cup of additional walnuts if you wish (these must not be roasted as they will cook while exposed to the heat during baking)
Bake for 16-18 minutes until golden and a cake tester or skewer inserted in center comes out clean
Leave to cool in the muffin tins for around 5 - 10 minutes. Then remove and let cool further on a wire cooling rack