Delicious sweet rolls, filled with lemon sugar and topped with a lemon glaze.
For the final dough: Add the starter dough to a large bowl or the bowl of a stand mixer fitted with a kneading hook. Add the yeast, milk, sugar, salt, egg and butter to the bowl. Mix to combine. Add 2 cups of the flour and mix to combine. Add additional flour 1/4 cup at a time until you have a smooth, moist dough. Remove dough to a greased bowl, cover and let rise until doubled, about 45-60 minutes.
Remove dough to a floured surface and roll into a rectangle 12x16 inches. Brush dough with melted butter, then scatter sugar/zest mixture evenly overtop. With the short edge of the dough closest to you, fold the top half of the dough down and over the bottom half, making an 12x8-inch rectangle. Using a sharp knife or a pizza cutter, cut the dough into twelve 1-inch wide strips.
Take one strip of dough and holding both ends, twist 5 or 6 times. Tie your twisted strip into a knot, then take the two loose ends and tuck them underneath, pushing one end up through the centre of the knot to secure. Place on parchment lined baking sheet. Repeat with remaining strips of dough. Cover baking sheet with a tea towel and let rise until puffy, 30-40 minutes.