Preheat the oven to 400 degrees. Fill your muffin pan with 18 liners.
In a medium bowl, whisk together the flour, baking soda, baking powder and salt.
In a large bowl, whisk together the melted butter, sugar, eggs, sour cream, milk, vanilla and lemon zest.
Set aside ¼ cup of strawberries for topping your muffins. In a small bowl, toss the remaining strawberries with 1 tablespoon of flour.
Add the flour mixture to the butter mixture and mix until incorporated. Do Not Overmix. The batter will be thick.
Fold the strawberries that have been tossed in flour into the batter.
Fill the muffin liners with the batter, filling each one until almost full. TIP: use a large scoop or spatulas sprayed with non-stick spray to get the batter evenly into the liners.
Add a few pieces of strawberry (from the reserved ¼ cup diced strawberries) to the top to each of the muffins. Sprinkle the reserved 1 tablespoon granulated sugar evenly between the tops of the muffins.
Bake the muffins for 17 - 20 minutes, or until the tops are golden brown. A toothpick inserted in the middle of a muffin should come out clean.
Cool in the muffin pan for 15 minutes. Remove and cool completely on a cooling rack (especially important if making gluten-free).