Preheat oven to 175 degrees and grease 12 muffin hole tin.
Mix dry ingredients together - flour, sugar, baking powder, bicarb of soda, salt, cinnamon. Make a well in the middle.
Mix wet ingredients together - butter, yoghurt, egg, vanilla and pour into the dry mixture well.
Add sliced strawberries and gently fold mixture until combined. Don't over mix.
Divide batter into muffins holes and top with extra strawberry slices and a sprinkle of sugar.
Pop in oven for 20-25 minutes or until a skewer poked into middle of the muffin comes out clean.
Rest the muffins in the tin for 5 mins then turn out onto cooling rack.
Muffins come out a little soft but will firm up on cooling.