Warm the milk: In a microwave-safe bowl, warm the milk in the microwave for about 1 minute, until it’s between 98°F to 105°F.
Mix the Wet Ingredients: In a large mixing bowl, whisk the warm milk with the sugar, instant yeast, eggs, and softened butter.
Add the Dry Ingredients: Sprinkle the flour, cinnamon, and salt over the top of the wet ingredients. Mix everything with a large wooden spoon until it forms a shaggy dough.
Knead the Dough: On a clean work surface, knead the dough by hand for about 5 minutes, until the dough is smooth and elastic. (Or knead the dough in a stand mixer with a hook attachment for about 3 minutes.)
Let the Dough Rise: Place the dough ball back in the mixing bowl and cover it with a clean kitchen towel. Let the dough rise in a warm spot until it has doubled in size, after about 1 hour.
Make the Filling: Mix the brown sugar, granulated sugar, cinnamon, optional nutmeg or cloves, and salt in a bowl. Set aside.
Roll out the Dough: Grease a 9-inch by 5-inch loaf pan and set aside. On a clean work surface, roll out the dough until it’s a rectangle that measures 12 inches by 16 inches.
Add the Filling: Brush 2 tablespoons of melted butter evenly over the dough, all the way to the edges. Sprinkle the sugar and cinnamon mixture evenly on top.
Shape the Loaf: Cut the dough into 12 even squares (4 inches by 4 inches) (3 squares by 4 squares). Fold each square of dough in half and place it in the prepared loaf pan so the folded side is facing down in the pan, and the open side showing the filling is facing up. To get all the dough pieces to fit, gently press the ones in the loaf pan towards the side to make room for the rest.
Proof the Dough: Cover the loaf pan with a kitchen towel. Set aside to proof for 30 minutes to 1 hour, until the loaf has puffed up. The dough is done proofing when an indent made by your finger springs back to its original shape after 2-3 seconds.
Bake the Bread: Preheat the oven to 350°F and place a metal baking sheet on a lower oven rack to catch any overflowing filling. Bake for 45 to 55 minutes, until the loaf is golden brown and reaches an internal temperature of at least 180°F. Add a large piece of aluminum foil folded in half over the bread after 20 minutes, to prevent the top from getting too brown. Allow the loaf to cool for 10 minutes, then remove it from the loaf pan and allow it to cool for another 20 minutes. Add the Glaze: In a small bowl, whisk the powdered sugar, salt, and one tablespoon of milk. If it’s too thick to drizzle, add another teaspoon of milk at a time. Drizzle the glaze on top of the loaf, allowing it to drip down the sides.