To make the dough: Combine milk, yeast, and sugar in a large mixing bowl and mix on low speed until incorporated. Add the salt, eggs, and melted butter and mix until combined. Gradually mix in the flour until the dough comes together and pulls away from the side of the bowl. The dough will be sticky. Remove the dough from the bowl and place on a lightly floured surface. Kneed into a smooth ball. Grease a large bowl and add the dough to the bowl. Cover the bowl with plastic wrap and let sit 45 minutes-1 hour or until the dough has doubled in size.Meanwhile, make the filling. Add the brown sugar and cinnamon to a bowl and mix well.Lightly dust a surface with flour. Once the dough has doubled in size, punch the dough down and roll the dough into a rectangle (about 9x24 inches). Drizzle half the butter evenly over the dough. Sprinkle with half the cinnamon sugar. Arrange the apples over the cinnamon sugar, then sprinkle with the remaining cinnamon sugar and drizzle with the remaining butter. Starting with the long edge closest to you, pull the edge up and over the filling and carefully roll the dough into a log, keeping it fairly tight as you go. When you reach the edge, pinch along the edges to seal.5. Place the log seam side down on a baking sheet lined with parchment paper. With a pair of sharp kitchen scissors cut diagonal slices almost to the bottom of the log. Arrange the cut sections so that they lean to alternating sides. Use your hands to gently push the dough together to almost the size of you bread pan. The dough will zigzag slightly. Using the parchment paper, lift the dough up and into the bread pan. If using a bread pan smaller than 9x5 inches, divide the dough among 2 bread pans. Cover and let rise in a warm place for 45 minutes to 1 hour.Preheat the oven to 350 degrees F. Place the bread on a rimmed baking sheet and bake 45-50 minutes or until lightly browned on top, do not over bake, this bread is best when still doughy. To make the glaze. In a medium bowl, whisk together the maple syrup, powdered sugar, and bourbon, if using, and vanilla. If needed, add water to thin the glaze, 1 tablespoon at a time. 8. Serve the bread warm, drizzled with the glaze. Leftovers are great the next day!