Preheat the oven to 400ºF / 200ºC / Gas Mark 6 and place muffin papers into a 12-hole muffin
pan. Melt the butter in a small saucepan, then set aside to cool slightly.
Place the sifted flour, baking soda (bicarbonate of soda), baking powder, and cinnamon in a
large bowl and stir to combine. Add the sugar and a pinch of salt and stir again.
Whisk the cooled melted butter, buttermilk, and egg together in another bowl, then pour this
mixture into the dry ingredients and deftly mix, but don't over mix. Fold in the blueberries and
spoon the batter into the muffin papers. Bake for 20 minutes. Leave to cool, then drizzle with
icing glaze, if liked.