In a large mixing bowl, combine flour, sugar, yeast, and salt. Make a well and add warm milk, egg, and butter. Mix until shaggy dough forms and knead for 12-15 minutes until smooth.

Shape dough into a ball, place in greased bowl, cover, and let rise for 1 hour until doubled. Roll into 1/2 inch thick rectangle. Spread butter over two-thirds, fold and chill for 30 minutes.

Roll out dough again, repeat butter application and folding process twice, chilling for 30 minutes each time.

Roll chilled dough into 1/4 inch thick rectangle. Spread filling evenly and roll into a log. Cut into segments, twist, and place upright in greased muffin tin.

Cover and let rise at room temperature for 30-45 minutes. Refrigerate overnight for enhanced flavor if desired.

Preheat oven to 375°F (190°C). Bake for 25 minutes until golden brown.

Roll cruffins in sugar and cinnamon mixture while hot, and allow to cool slightly before serving.