Add the flour and milk to a microwave safe bowl and whisk them together. Microwave for 30 seconds, then stir and microwave for another 30 seconds. The mixture should now be a thick slurry, but if it’s not, microwave it in 10 second intervals until it has thickened.
Brioche Dough
Add the milk, sugar, yeast, egg, flour, salt, butter, and tangzhong to the bowl of a stand mixer fitted with the dough hook attachment.
Knead the mixture on medium speed for ~15-20 minutes. The dough is ready when it is no longer sticking to the sides or the bottom of the bowl, and passes the windowpane test.**
Once the dough is done kneading, shape it into a ball and place it back into the mixing bowl. Cover the mixing bowl with plastic wrap and place it in a warm area to rise until doubled in size (~1 hr.)***
Once the dough has finished rising, lightly punch it down to remove any excess air in it.
Transfer the dough to a clean, lightly floured surface. Divide the dough into 8 equal pieces, and roll each piece tightly into a ball.
Transfer the buns to a parchment lined baking sheet, spacing them apart to allow room for spreading. Leave the buns in a warm environment until they puff up a little, ~30 minutes. In the meantime, make the streusel.
Streusel
In a small microwave safe bowl, melt the butter. Add in the sugar and flour, then stir the mixture together until you have little clumps of dough. Set aside.
Cheesecake Filling
In a small bowl, whisk the egg.
Add the cottage cheese, 1 tbsp. of the whisked egg, sugar, and vanilla to a food processor. Process the mixture until it’s fully smooth and combined.
With the remaining egg, make an egg wash by whisking in 1 tbsp. of milk into the egg.
Once the buns have puffed up, preheat the oven to 350°F / 175°C. Lightly flour the bottom of a cup or bowl that is ~3” in diameter. Press the cup down onto each of the pastries to form a divot for the filling.
Pour 1 ½ tbsp. of the cheese filling into the center of each bun. Then, top the cheese with 1 ½ tbsp. of strawberry jam and swirl it around.
Brush the edges of each of the buns with the egg wash, then sprinkle the streusel over the edges.
Bake for 15-20 minutes, or until the edges of the buns turn golden brown. Serve and enjoy!
Notes
*You could substitute in cream cheese here. You won't need a food processor to blend it up if using cream cheese - just beat the ingredients together in a mixing bowl.**Take a small piece of dough and stretch it gently as far as you can. If it tears super easily, keep kneading. If it's able to spread to the point where it's super thin and you can see light through it, it has passed the windowpane test and is good to go!***At this point you could leave the dough in the fridge overnight, and proceed with the rest of the recipe the next day.