1-Preheat the oven to 425 F, line: Preheat the oven to 425 F, line the cupcake pan with paper liners, and set aside. This recipe makes 9-10 muffins.
2-Divide the blueberries in half: Divide the blueberries in half. Toss ¾ cup of blueberries with 1 Tablespoon flour. Reserve the remaining ¾ cup of blueberries for topping. Set them aside.
3-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.
4-To make the muffins, in a bowl,: To make the muffins, in a bowl, stir together flour, baking powder, and salt, and set aside.
5-In a large bowl, whisk together egg: In a large bowl, whisk together egg and granulated sugar until combined. Whisk in yogurt, oil, and vanilla extract.
6-Add dry ingredients to wet ingredients and: Add dry ingredients to wet ingredients and mix everything together by hand.
7-Finally, using a rubber spatula, fold in: Finally, using a rubber spatula, fold in blueberries (3/4 cup blueberries tossed with 1 Tablespoon flour). Reserve ¾ cup blueberries for topping.
8-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.
9-To assemble the muffins, add about 1: To assemble the muffins, add about 1 ½ Tablespoons of muffin mixture to each cup. Using a spoon, spread the mixture up the side of paper liners to make a small dent in the center. Drop 1 not quite a full Tablespoon of cream cheese mixture in the center of each muffin. filling each cup about 2/3 to ¾ full.
10-Add a few blueberries on top, then: Add a few blueberries on top, then generously top each muffin with streusel crumbs. Add a few more blueberries on top and gently press the crumbs to stick to the muffin batter.
11-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.
12-Cool 5-10 minutes in the pan, then: Cool 5-10 minutes in the pan, then transfer the muffins to a rack to cool completely.
13-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 the desired consistency is reached. Drizzle over muffins and serve.