Kalács (Hungarian Cinnamon Swirl Bread)

Grease a large bowl and set aside. Grease 2 glass loaf pans and set aside.

Place flour, white sugar, salt, and yeast in the bowl of a stand mixer fitted with the dough hook attachment. Whisk together warm milk, egg, 1/4 cup melted butter, and vanilla in a medium bowl until well combined; pour into flour mixture. Mix on low until flour is moistened and a dough forms, then increase speed to medium and continue kneading until smooth and elastic, 4 to 5 minutes.

Place dough into the prepared bowl; cover and let rise in a warm place until doubled in bulk, about 1 hour 30 minutes.

Punch down dough, turn out onto a floured work surface, and divide into 2 equal pieces. Roll each piece into a 1/3-inch-thick rectangle. Brush each square with melted butter. Mix together brown sugar and cinnamon in a small bowl until well combined and sprinkle evenly over buttered rectangles.

Roll each rectangle firmly into a log, pinch the ends closed, and tuck underneath. Place into the prepared loaf pans. Cover and let rise in a warm place until doubled in bulk, about 45 minutes.

Preheat the oven to 350 degrees F (175 degrees C).

Brush the tops of loaves with melted butter.

Bake in the preheated oven until loaves are golden brown and sound hollow when tapped, about 30 minutes.