Whisk the warm milk, yeast, and sugar together in the bowl of a stand mixer fitted with a dough hook attachment. Cover and allow to sit for about 5 minutes or until foamy.

Add the butter, 2 cups of flour, and the salt. Beat on medium speed for 2 minutes, scraping down the bowl as needed. Add the remaining 1 cup of flour and beat on low speed until a soft dough forms.

Keep the dough in the mixer and beat for an additional 5 full minutes, or knead by hand on a lightly floured surface for 5 minutes.

Lightly grease a large bowl with oil. Place the dough in the bowl, turning to coat all sides. Cover and allow to rise for around 2 hours or until nearly double in size.

Gently punch down the dough and place it on a lightly floured surface. Flatten into a 10×14-inch rectangle. Cover and chill in the refrigerator for 20 minutes.

Beat 1 cup of softened salted butter and 1 tablespoon of flour together until combined. Keep flour at hand for rolling.

Remove dough from the refrigerator. Spread the butter down the center third of the dough. Fold the edges over the butter and seal.

Roll the dough into a 9×12-inch rectangle. Fold again like a business letter, cover, and refrigerate for 20 minutes.

Repeat the rolling and folding process two more times, refrigerating for 20 minutes after each lamination.

Lightly grease a standard 12-cup muffin pan. Mix together the sugar and cinnamon in a medium bowl.

Place the chilled dough on a cutting board and cut into 3 equal rolls. Roll out one portion into an 8×12-inch rectangle and sprinkle with 2 tablespoons of cinnamon-sugar.

Cut the dough into 12 strips, layer three strips, roll them up together, and tuck the ends underneath. Place in the muffin pan. Repeat with remaining dough.

Cover cruffins lightly and allow to rise for 1 hour until puffy.

Preheat the oven to 350°F and bake for 25–28 minutes, until the internal temperature reaches 200°F.

Let the cruffins cool slightly in the pan, then roll in remaining cinnamon-sugar. Fill with desired fillings using a piping bag.