Preheat the oven to 190°c (170 fan/ 375F/ Gas 5) and line a 12 hole muffin tin with muffin cases.
Place the dry ingredients in a large mixing bowl
140 g Caster Sugar, 200 g Plain Flour, 1 teaspoon Bicarbonate of Soda
Whisk the wet ingredients together in a jug.
100 ml Natural Yogurt, 140 g Butter, 2 Eggs
Gently mix the wet ingredients into the dry ingredients then fold in the blackberries and lemon zest.
150 g Blackberries, 1 Lemon
Spoon the batter into the muffin cases and bake in the oven for 16-18 minutes.
Whilst the muffins are in the oven make the lemon glaze. Put the icing sugar in a bowl and whisk in the juice of 1 lemon. Add a few teaspoons of lemon juice at a time. You might find that you don't need all of the lemon juice. It should be a thin glossy consistency, perfect for drizzling. Drizzle over the cooling muffins and allow to set.
100 g Icing Sugar, 1 Lemon