Preheat oven to 375 degrees. Add paper liners to a 12 serving muffin tin and set aside.
Combine flour, baking powder, baking soda, sugar and salt in a large mixing bowl. Whisk until combined.
Cut in butter using two knives or a pastry cutter until butter is pea-sized. Set aside.
In a separate bowl whisk together egg, buttermilk and vanilla.
Add wet ingredients to dry then mix with a wooden spoon until just barely combined. Do not overmix.
Gently fold in strawberries with a rubber spatula.
Distribute batter evenly among muffin liners.
Bake for 20 minutes or until muffin tops are golden brown and a tester placed in the center comes out clean.
Keeping the muffins in the pan, place on a wire rack to cool completely.
Serve plain, with a dusting of powdered sugar or with strawberries and dollop of whipped cream.
Store muffins at room temperature up to 3 days.