Preheat oven to 375°. Line 12 regular muffin tips with paper cups, and spray cups with nonstick cooking spray.
Stir together the flour, sugar, baking powder, baking soda, and salt in a large bowl. Set aside.
Whisk together the melted butter, eggs, yogurt, and vanilla in a medium bowl. Add the wet ingredients to the dry ingredients; stir together just until combined. Fold in 1 ½ cups of the strawberries. (Batter will be thick.)
Using a 2 ¼-inch scoop, drop a level scoop of batter into each lined muffin cup. Top scooped batter evenly with the remaining ½ cup berries; sprinkle with turbinado sugar, if desired.
Bake until tops are golden brown and wooden pick inserted in the center of a muffin comes out clean, 20 to 22 minutes. Serve muffins with strawberry butter, if desired.
