In a medium bowl, mix together 1/2 cup of flour, 1/4 cup of light brown sugar, and a pinch of salt. Melt 2 tablespoons of unsalted butter and pour it over the dry ingredients, stirring until the mixture resembles crumbly sand. Set aside for later.

In a separate bowl, blend together 6 oz of softened cream cheese, 1/4 cup of granulated sugar, 1 tablespoon of cornstarch, and a splash of vanilla extract until the mixture is smooth and creamy.

In a large mixing bowl, whisk together 2 cups of all-purpose flour, 1 1/2 teaspoons of baking powder, and 1/4 teaspoon of salt.

In another bowl, beat 1 large egg with 1/2 cup of granulated sugar until pale and fluffy. Add in 1/2 cup of Greek yogurt, 1/4 cup of vegetable oil, and a teaspoon of vanilla extract. Mix until combined.

Fold the wet ingredients into the dry ingredients gently until just combined. Near the end of the mixing, gently fold in 3/4 cup of your mixed berries.

Preheat your oven to 350°F (175°C). Line a muffin tin with paper liners or grease it lightly. Using a scoop, add a spoonful of muffin batter to each cup, create a dent in the center, fill with your creamy filling, and cover with more batter and streusel topping.

Place the muffin tin in the oven and bake for 30-35 minutes or until golden brown and a toothpick inserted comes out clean.

Once baked, let the muffins cool in the pan for 5-10 minutes before transferring them to a wire rack to cool completely.

In a small bowl, whisk together 3/4 cup of powdered sugar with a few teaspoons of milk or cream until it reaches your desired glaze consistency.