Preheat the oven to 400*F/200*C/ gas mark 6. Butter a muffin tin really well, or line it with paper liners. (I used a six-cup muffin tin and 2 ramekins.)
Measure the flour and baking powder into a bowl and give it a good stir. Drop in the butter and then rub it into the flour with your fingertips until the mixture resembles fine dry bread crumbs. Stir in the lemon zest, sugar, and blueberries.

Mix the eggs and milk together and then add to the dry ingredients, stirring all together just until the mixture is combined. It's okay if the batter is a bit lumpy. In fact, this is desirable.
Spoon the batter into the muffin cups filling them almost to the top.
Bake for 20 to 25 minutes until well risen and golden brown. A toothpick inserted in the center should come out clean and they should spring back when lightly touched.

Leave to cool for a few minutes, then tip out onto a wire rack to cool for a bit longer.
Beautiful served warm with a nice hot cuppa! ready to Serve.