In a large bowl add yeast, 1 tsp (5g) sugar and ¼ cup (60ml) lukewarm milk. Let it rest for 5 minutes to activate the yeast.
Add the rest of the ingredients, flour, sugar and salt, the remaining milk, egg, vanilla extract and softened butter.
Start kneading for about 5-7 minutes, until smooth and slightly pulls away from the sides of the bowl.
Transfer the dough into an oiled bowl and cover with plastic wrap.
Let the dough rest for about 1 hour at room temperature (warm space) until doubled in size.
Divide the dough into 12 equal pieces.
Shape each into a bun and place on a parchment paper-lined baking sheet.
Cover with a kitchen towel and let the buns rest for 15-20 minutes.
Meanwhile, preheat the oven to 350°F (180°C).
In a medium bowl, whisk together the cream cheese with powdered sugar, egg and vanilla extract.
Transfer to a piping bag fitted with a plain tip.
Press each bun using a glass dipped in flour to create a well for the filling.
Divide the cream cheese filling between the buns.
Top with fresh blueberries.
Brush the edges with beaten egg.
Bake the cream cheese buns for about 20 minutes or until nicely golden.
Transfer to a wire rack to cool slightly.
Dust with powdered sugar and enjoy!
