Preheat oven to 350 degrees F. Line a large baking dish with parchment paper; set aside.
In a large bowl or stand mixer, mix dough ingredients until a thick dough forms; set aside. In a separate bowl, beat cream cheese until smooth then mix in remaining filling ingredients until well combined.
Roll out dough onto a lightly floured surface into a large rectangle (approximately 10”x14”). Spread cream mixture down the center of the dough, leaving 2-3 inches on each side, then top with fresh blackberries.
Use a pizza cutter to cut 1-inch diagonal strips down each side of the dough. Fold strips up and over the filling, alternating sides to create a braid. Whisk egg and brush on the top and sides of the braid then bake for 25 minutes.
In a small bowl, whisk together all glaze ingredients then drizzle glaze on top of braid when finished cooking. Let cool slightly, then cut into slices and serve.