In a saucepan, whisk together the milk, sugar, honey, and melted butter. Heat until warm (about 100°F, like a warm bath).
Mix the yeast into the milk mixture. Cover with a towel and let it activate until foamy and frothy, up to 20 minutes. (If the mixture is too hot, it will kill the yeast!)
In a large bowl, combine 5 cups of flour, salt, and baking powder. Pour in the yeast mixture.
Mix with a wooden spoon until just combined. Cover the bowl and let the dough rise in a warm place for about 1 hour, until it doubles in size.
Preheat the oven to 340°F.
Add the remaining flour to the dough. Stir well, then turn it out onto a well-floured surface.
Knead the dough lightly, adding more flour as needed, until it loses its stickiness.
Roll the dough into a large rectangle.
Mix the filling ingredients together and spread evenly over the dough.
Cut the dough into 4 or 5 strips. Roll the strips into one another to form a giant roll.
Place the roll in a lined and greased 7-inch springform pan. Cover and let it rise again in a warm place for 45 minutes.
Remove the cover and bake the roll in the preheated oven for 30-40 minutes until well-risen and golden brown. If the center is still undercooked after 25 minutes, cover with foil and continue to bake, checking every 10 minutes.
For the glaze, slowly add the milk and honey into the powdered sugar until you reach your preferred consistency.
Cover the honey bun with the glaze while still warm. Let it set for about 30 minutes before serving. Enjoy!