1. In a mixing bowl, combine flour, sugar, salt, and yeast. Add warm water and softened butter. Knead for 6–8 minutes until smooth and elastic. Let rise for 45–60 minutes.

2. Meanwhile, flatten cold cubed butter between parchment into a 6x8 inch rectangle. Keep chilled.

3. Roll risen dough into a 12x18 inch rectangle. Place butter in the center, fold like an envelope, and roll gently. Fold in thirds like a letter. Chill 30 minutes.

4. Repeat rolling and folding twice more, chilling for 30 minutes between folds.

5. Roll dough to 12x14 inches. Spread optional filling, then cut into 1-inch strips. Roll each strip into a spiral and place into greased muffin tin. Let rise 45–60 minutes.

6. Preheat oven to 375°F (190°C). Bake for 20–25 minutes, until golden and flaky.

7. Let cool 10 minutes in the tin, then transfer to a wire rack. Dust with powdered sugar and serve warm or at room temperature.