1-Preheat the oven to 425 F, line: Preheat the oven to 425 F, line cupcake pan with paper liners ad set aside.
2-To make the crumb topping, stir together: To make the crumb topping, stir together flour, sugar, and salt. Add melted butter and whisk with a fork until coarse crumbs form. Set aside.
3-To make the muffins in a large: To make the muffins in a large bowl stir together flour, baking powder and salt and set aside.
4-In a medium bowl, whisk together egg: In a medium bowl, whisk together egg and granulated sugar until combined. Whisk in yogurt, oil, and vanilla extract (mixture should be pale and yellow).
5-Fold wet ingredients into dry ingredients and: Fold wet ingredients into dry ingredients and mix everything together by hand.
6-Finally, using a rubber spatula, fold in: Finally, using a rubber spatula, fold in diced strawberries. Reserve 2-3 tablespoons of diced strawberries to top the muffins.
7-To make the cream cheese filling, mix: To make the cream cheese filling, mix softened cream cheese, sugar, corn starch and vanilla just to combine.
8-To assemble the muffins, add 1 Tablespoon: To assemble the muffins, add 1 Tablespoon of muffin mixture in each cup. Drop 1 not quite full Tablespoon of cream cheese mixture in the center of each muffin. Cover cream cheese filling with muffin batter, filling each cup about 2/3 to ¾ full.
9-Generously top each muffin with streusel crumbs: Generously top each muffin with streusel crumbs. Add a few strawberry pieces on top and gently press the crumbs to stick to the muffin batter.
10-Place in preheated oven and reduce the: Place in preheated oven and reduce the temperature to 350 F. Bake 22-25 minutes, or until the tops are golden brown and the center has set.
11-Cool 5-10 minutes in the pan, then: Cool 5-10 minutes in the pan, then transfer the muffins on a rack to cool completely.
12-Meanwhile, prepare the glaze: Meanwhile, prepare the glaze. Stir powdered sugar with milk or cream. Start with 1 teaspoon of the liquid and gradually add more until desired consistency has reached. Drizzle over muffins and serve.