Preheat oven at to 365°F at step 10.
Cover a large baking sheet with parchment paper, lightly spray with baking spray. Set aside. In a small saucepan, add butter, salt, sugar and milk, heat until very warm but not hot (no warmer than 100 degrees).
Remove from heat and add whisked eggs and yeast, stir to combine. Cover saucepan and allow yeast to activate, about 5 minutes.
Add flour to saucepan and mix to combine. Transfer dough to a large greased mixing bowl and cover (if the saucepan used was large, keep dough in there). Allow the dough to rise 1 1/2 hours or until doubled in size.
Combine cream cheese and sugar.
Dust surface with flour and roll out the dough to a rectangle, about 13" x 20" in size. The dough will be slightly sticky, keep surface and top of dough floured. Spread poppy seed filling over the dough. Spread cream cheese mixture over poppy seed.
Roll up dough into a log, bring log together to create a wreath and bring together ends of log and secure seems.
Pull out on the wreath to stretch the dough.
With kitchen shears, cut slits in the dough about ½” - ¾” apart. Shape cut slits into a wreath (see pictures and video) and brush with egg wash. As you are shaping the wreath pull dough away.
Rise for 1/2 hour.
Bake until top of babka is golden, about 18-22 minutes.
Once cooled, dust with powdered sugar, optional.