Add the flour to a large bowl. Dissolve the dry yeast in lukewarm milk and stir the mixture into the flour, along with the egg, sugar, and butter. Knead the dough until smooth, form it into a ball, cover the bowl, and let sit for 45 minutes.
Flour your work surface and roll the dough out into a circle. Place a large pot lid in the middle of the dough and make several vertical incisions in the dough around the pot lid – these will be the fringe pieces.
Remove the pot lid from the center section of dough and select a section of 3 fringe pieces – piece 1 is on the left, piece 2 is in the middle, and piece 3 is on the right. Fold piece 1 onto the center section of dough at a slight angle to the right, like a slash. Fold piece 3 over piece 1 to form an X. Then fold piece 2 over piece 3. Continue braiding the rest of the fringe pieces in this manner until the entire outer section of dough is braided. Carefully transfer the dough to a baking tray lined with parchment paper and let sit for 15 minutes.
Poke several holes in the center section of dough with a fork and brush the egg wash over the outer braided section of dough.
Combine the softened cream cheese, sugar, egg, corn starch, and vanilla and spread the mixture over the center section of dough.
Transfer the baking tray to a preheated oven and cook at 325°F for 35 minutes. Let the braided berries & cream pie cool and garnish with fresh mixed berries and powdered sugar.