In a bowl for the electric mixer, stir together flour, powdered sugar, yeast, and salt. Add the egg yolks, melted butter and milk, and stir with a wooden spoon to combine. Attach a dough hook to the mixer and knead the dough for 3 minutes.
Transfer the dough into a lightly greased bowl and cover tightly with a plastic wrap. Punch a hole for ventilation and cover with a towel. Let the dough rise in a warm place until double in volume, about 1 hr.
Punch the dough to remove the gas. Form the dough into a log and cut into 12 equal pieces. Form each dough piece into a ball shape and place in a half sheet pan lined with a parchment paper, place them apart. You should be able to fit all 12 pieces in a pan.
Flatten down each dough balls with your fingers, then using a glass bottom or anything that has 2.5-inch diameter on a flat surface, press down to leave an indentation. Cover them with a towel and let it rise second time until double in volume.
Meanwhile prepare the cheese filling by mixing all the ingredients in a bowl; set aside.
To make the streusel, mix flour, sugar and salt in a small mixing bowl. Add the melted butter and combine together with your fingers until it forms fine crumbs; set aside.
For the fruit jam filling, mix jam and water and microwave for 7-10 seconds to loosen; Set aside.
Preheat the oven to 375˚F.
When the dough pieces are risen again, press again with a glass bottom to leave deeper indentation. Be careful not to deflate the dough. Brush with egg wash.
Fill each piece with 1 tablespoonful of cheese filling, and 2 teaspoonful of jam filling and sprinkle with streusel topping all over. Bake in the preheated oven for 20 minutes or until the edges are golden brown. Let them rest in a pan for 5 minutes, then transfer on to a cooling rack. Serve warm or at room temperature.