Preheat oven to 375°F and prepare a 12-cup muffin tin with paper liners or grease lightly.
In a small bowl, combine cream cheese, 2 tablespoons sugar, egg yolk, and 1/2 teaspoon vanilla until smooth. Set aside.
Whisk together 2 cups flour, 2/3 cup sugar, baking powder, baking soda, and salt in a large bowl.
In a separate bowl, beat eggs, milk, vegetable oil, and 1 teaspoon vanilla until well blended.
Add wet ingredients to dry ingredients and stir gently until just combined; do not over-mix.
Toss diced strawberries with 1 tablespoon flour to coat, then fold into the batter.
Mix crumb topping by combining flour and sugar, then stirring in melted butter until crumbly.
Fill muffin cups halfway with batter, add about 1 teaspoon of cream cheese filling to center, then cover with remaining batter.
Generously sprinkle crumb topping over each muffin.
Bake for 18 to 22 minutes until golden brown and a toothpick inserted into the muffin part (not the filling) comes out clean.
Cool muffins in the tin for 5 minutes before transferring to a wire rack to cool completely.