Preheat the oven to 200°C, 400°F, Gas 6.
Grease a mini muffin tray or line with muffin cases and set aside. Melt the butter and reserve. In one bowl combine the dry ingredients.
Pour the milk in to a measuring jug and crack in the egg and whisk with a fork to amalgamate.
Pour the liquid ingredients into the dry ingredients, stirring with a wooden spoon. The batter should remain somewhat lumpy – do not whisk until smooth. Add the stem ginger to the batter and stir in.
Pour into the muffin cases and bake in the oven for about 10-15 minutes.
Remove to a wire rack and allow to cool a little.