01 - Preheat oven to 400°F. Line a 12-cup muffin tin with paper liners or grease thoroughly with cooking spray.
02 - In a large bowl, whisk together flour, baking powder, baking soda, and salt until evenly distributed.
03 - In a separate bowl, whisk oil or melted butter, sugar, eggs, milk, and vanilla extract until smooth and well combined.
04 - Pour wet ingredients into dry ingredients. Gently fold together until just combined—batter should remain slightly lumpy. Do not overmix.
05 - Gently fold diced strawberries into batter until evenly distributed throughout.
06 - Divide batter evenly among prepared muffin cups, filling each about ¾ full.
07 - Sprinkle tops generously with coarse sugar for crunchy texture.
08 - Bake for 22–25 minutes until tops are golden brown and a toothpick inserted into the center comes out clean.
09 - Let muffins cool in pan for 5 minutes, then transfer to wire rack to cool completely before serving.