Preheat oven to 425°F (220°C). Line a 12-cup muffin pan with paper liners. This recipe makes about 9–10 muffins, so you’ll have a couple of empty cups.
Make the streusel topping. In a small bowl, mix flour, brown sugar, and salt. Pour in melted butter and gently stir with a fork until you get crumbly, uneven bits. Don’t overmix — you want a sandy, chunky texture. Set aside.
Prepare dry ingredients. In a large bowl, whisk together flour, baking powder, and salt so everything is evenly combined.
Mix wet ingredients. In another bowl, whisk the egg and sugar until slightly pale and smooth. Then add Greek yogurt, vegetable oil, and vanilla. Mix until everything looks creamy and well blended.
Combine wet and dry. Pour wet mixture into dry ingredients. Fold gently using a spatula until just combined. Stop as soon as you don’t see dry flour — overmixing will make muffins dense.
Add strawberries. Gently fold in diced strawberries. Be careful not to crush them too much. Save a small handful for topping later so muffins look bakery-style.
Make cream cheese filling. In a small bowl, mix cream cheese, sugar, vanilla, and cornstarch until completely smooth and creamy. No lumps should remain — this is your soft cheesecake center.
Assemble muffins. Add a spoonful (about 1/3) of batter into each liner. Add a teaspoon of cream cheese filling in the center, then cover it with more batter until the cups are about 2/3 to 3/4 full. Make sure filling is fully covered so it doesn’t leak or brown.
Add toppings. Sprinkle streusel generously over each muffin. Press lightly so it sticks. Add a few reserved strawberry pieces on top for a fresh, bakery look.
Bake. Place muffins in the oven at 425°F, then immediately reduce temperature to 350°F (don’t wait). Bake for 22–25 minutes, or until tops are golden and a toothpick comes out clean from the muffin part (not the filling).
Cool completely. Let muffins rest in the pan for 5–10 minutes, then transfer to a wire rack. Allow them to cool fully before glazing so the glaze doesn’t melt.
Glaze and finish. Mix powdered sugar with milk or cream, adding liquid slowly until you get a smooth drizzle consistency. Drizzle over cooled muffins and let it set before serving.
