In the bowl of your stand mixer with dough hook attached, add flour, salt, sugar, yeast, 2 eggs plus 2 yolks and milk. Mix on low until a rough dough comes together.
Cut your room temperature butter into about 5 equal pieces, and with the mixer running on low, add the butter chunks one at a time. Do not add the next piece until the previous has been thoroughly mixed into the dough. Repeat until all butter is incorporated in.
Mix dough until smooth, and passes the window pane test. As this is a very enriched dough, kneading could take anywhere from 15-30 minutes. I leave my mixer going and check on the dough every 7-10 minutes.
When the dough is ready, it will still be sticky but also a little slick from the large amount of butter. Place into a very lightly greased bowl, cover and allow to rise in a warm place for 90-120 minutes.
Line two baking sheets with parchment and set aside.
When your dough is ready, punch down and transfer a floured work space.
Using a knife or a bench scraper, divide your dough into 12 equal portions. Use a scale if you would like very evenly sized dough portions. For me, it came out to about 73g per dough ball. Cover the dough while you work on shaping each piece.
Taking one piece of the dough, place in your palm and take the edges of the dough, folding them in towards the center. Once you have pulled all the sides in, pinch the center together and place the dough ball, seam side down, onto the your prepared baking sheet. Place 6 buns on each sheet. Repeat steps with remaining dough.
Cover your baking pan with your shaped buns and allow to rise for another 45-90 minutes in a warm place. Rolls are sufficiently proofed when they have puffed up considerably.
Preheat your oven to 375°F
In a medium size bowl, add your cream cheese, powdered sugar, and vanilla and mix for about one minute, until creamy and smooth.
Flour the bottom of a small cup or mason jar that is about 2¼ inches wide at the bottom. Press into the center of each bun creating a well in the center.
Fill each well with about 1½ tbsp of the cream cheese mixture and about 1 tsp of jam. Repeat with all buns.
Take the egg whites you reserved and brush the edges of your buns.
Place your baking pan on the center rack of your oven and bake your rolls for about 20 minutes. If you have to use two racks, switch the sheet pans half way through the bake. The bread will be a darker golden brown color when they are ready.
Remove from the oven and allow bread to cool for at least 20 minutes before enjoying. Lightly dust with powdered sugar before serving. Store in an airtight container.
