1. Prepare your oven and muffin tin: Preheat your oven to 375 F (190 C). Line a 12-cup muffin tin with paper liners or grease it well. This prevents sticking and makes cleanup easier.

2. Combine dry ingredients: In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, baking powder, and salt. Make sure there are no lumps and everything is evenly distributed.

3. Mix wet ingredients: In a separate medium bowl, whisk together the plain yogurt (or sourdough discard), milk, melted and cooled butter, large egg, and vanilla extract until well combined and smooth.

4. Combine wet and dry mixtures: Pour the wet ingredients into the dry ingredients. Stir gently with a spatula or wooden spoon until *just* combined. It’s crucial not to overmix; a few lumps are perfectly fine. Overmixing can lead to tough muffins.

5. Fold in the strawberries: Gently fold in the diced fresh strawberries. Distribute them evenly throughout the batter without crushing them too much.

6. Fill muffin cups and add topping: Divide the batter evenly among the 12 prepared muffin cups. If using, sprinkle a little turbinado sugar on top of each muffin for a lovely crunchy crust.

7. Bake until golden: Bake for 20-25 minutes, or until the tops are golden brown and a wooden skewer inserted into the center of a muffin comes out clean.

8. Cool and serve: Let the muffins cool in the muffin tin for 5 minutes before transferring them to a wire rack to cool completely. Enjoy them warm or at room temperature.