In a medium bowl, whisk together flour, salt and baking powder.
2 cups all purpose flour, ½ teaspoon salt, 2 teaspoons baking powder
In a large mixing bowl, add in butter, sugars and lemon zest. With the paddle attachment, start beating on medium high for about 3 minutes (scrape the bowl with a spatula half way through) until light and fluffy.
½ cup softened butter, 1 cup granulated sugar, 1 tablespoon lemon zest, about the zest of 1 lemon
Add the eggs one at a time, mixing well after each addition (about 30 seconds). Scrape the sides of bowl to make sure everything is combined. Add vanilla extract and mix.
2 large eggs, at room temperature, 1 teaspoon vanilla extract
Mix in the dry ingredients in 3 parts, alternating with milk. This means, adding one third of the dry ingredients, mixing a little bit until incorporated, then adding half of the milk and mixing until combined. Then, add another one third of the dry ingredients, mix, add the rest of the milk, mix, and finally add the last part of the dry ingredients. So, we start and finish with the dry ingredients. Do not over-mix.
½ cup whole milk
Fold in the strawberries. Then cover the bowl and refrigerate for 30 minutes.
2 cups chopped strawberries
In the meantime, preheat the oven to 400℉, line a 12-cup muffin pan with papers.
Then we prepare the topping. In a small bowl, stir together flour, granulated sugar, brown sugar and salt.
2 tablespoons granulated sugar, 2 tablespoons light brown sugar, ⅓ cup all purpose flour, pinch of salt
Drizzle melted (but cooled) butter over the mixture and use a fork to toss the ingredients together. This will create a crumbly mixture. Set aside until ready to use.
1½ tablespoon unsalted butter, melted and cooled
After 30 minutes, take the muffin batter out of the fridge and fill each muffin liner about ¾ full. Sprinkle the tops with the streusel mixture and bake for about 15 minutes or until a toothpick comes out of a muffin clean. Allow them to cool down for about 5 minutes before transferring them on a cooling rack.