6Tbsp.buttersoftened, + extra to brush on bread when it comes out of the oven
1-1/2tsp.salt
5-1/2cupsflourall-purpose, + 1/2 more as needed
Cinnamon Filling:
4Tbsp.buttersoftened
1/2cupsugar
2Tbsp.ground cinnamon
Instructions
In a large bowl, add yeast and warm water; stir to dissolve. Add warm milk, sugar, eggs, butter, salt, and about 3 cups of the flour; on medium speed of a stand mixer, beat until smooth using paddle attachment.
Remove paddle attachment and replace with dough hook. On medium-low, stir in enough of the remaining flour to form a soft dough. Continue kneading the dough (with the dough hook), about 7-10 more minutes, until smooth and elastic. Cover and let rise in a warm place until doubled, about 1 hour.
Combine 1/2 cup sugar and 2 Tbsp. ground cinnamon in a small bowl; set aside. Grease 2 loaf pans, 9" x 5".
On a lightly floured work surface, turn out dough, knead a few times; divide in half. Take one of the halves and roll into an 18" x 8" rectangle. Spread dough with 2 Tbsp. softened butter; sprinkle with half of the cinnamon sugar mixture. Starting on one of the short sides, roll dough up, jelly-roll style; pinch seam to seal. Place roll, seam side down in one of the prepared loaf pans. Repeat process with the remaining dough. Cover with plastic wrap or clean tea towel and let rise in a warm place until doubled, about 1-1/2 hours.
Preheat oven to 350°.
Bake loaves in center of oven until golden brown; 30 to 35 minutes. Remove from pans and place on wire racks to cool.