Mix dough ingredients:

In a stand mixer bowl, whisk together flour, yeast, and sugar. Add 4 tablespoons of butter, water, vanilla extract, and one egg at a time, mixing with the dough hook.

Knead and let rise:

Knead on medium speed until the dough is soft and smooth. Cover with a kitchen towel and let it rise in a warm spot until doubled, 1-2 hours. For hand-mixing, refer to the notes.

Roll into rectangle:

Butter a work surface, then gently deflate the dough. Roll it into an 18x7-inch rectangle.

Spread butter and roll:

Spread the remaining 4 tablespoons of butter over the dough. Roll tightly from the short side to form a log.

Trim and cut rolls:

Trim the ends to straighten, then cut into 6 pieces. Roll the trimmings into small balls and place them on a greased baking sheet.

Arrange and proof:

Set the dough pieces on top of the balls with cut sides up. Flatten slightly with your palm. Cover with a towel and let rise for 30-40 minutes until puffy.

Preheat oven:

Preheat oven to 320°F (160°C) and position a rack in the center.

Bake until golden:

Bake the rolls for 20-25 minutes until golden brown.

Brush with butter and sugar:

Immediately after baking, while still hot, brush each roll with butter and sprinkle with sugar.

Cool on rack:

Transfer to a wire rack to cool. Serve warm or let cool completely and store.