Preheat oven to 425 °F (220 °C) and line a muffin tin with paper liners. Reduce oven temp to 350 °F (175 °C) once muffins are placed in oven.

Toss ¾ cup of blueberries with 1 Tbsp flour; reserve remaining berries for topping.

To make the streusel, whisk flour, brown sugar, and salt. Stir in melted butter until coarse crumbs form; set aside.

In a bowl, whisk together flour, baking powder, salt; set aside.

In another bowl, whisk egg with granulated sugar until combined. Stir in Greek yogurt, oil, and vanilla.

Fold dry ingredients into the wet mixture gently until combined. Fold in the floured blueberries.

Spoon about 1½ Tbsp batter into each muffin cup. Spread mixture up the sides to create a small dent in the center. Drop about a scant tablespoon of cream cheese mixture into each muffin.

Top each with more batter or directly add remaining blueberries, then cover generously with streusel crumbs. Gently press down to adhere.

Bake at 350 °F for 22–25 minutes, or until muffin tops are golden and center is set. Let cool in pan 5–10 minutes, then transfer to a wire rack to cool completely.

If using glaze, whisk powdered sugar with milk or cream until smooth. Drizzle over cooled muffins and serve.