In the bowl of a stand mixer fitted with a dough hook, combine 1 cup of the flour with the yeast, cracked wheat, salt, and sugar.
In a microwave-safe bowl or measuring cup, combine the water and the oil. Microwave on high for 30-45 seconds, until warm (but not hot). Add the warm water mixture and the sourdough starter to the dry ingredients. Beat for 4 minutes on medium speed. Gradually add the remaining flour, about 1/2 cup at a time, and knead for 5-7 minutes until the dough is smooth and elastic. Place in a lightly oiled bowl and turn to grease the top. Cover lightly with a tea towel and let rise until doubled in size, about a hour.
Turn the risen dough onto a lightly floured surface and gently press or "punch" down to remove air bubbles. Divide the dough into 8 equal pieces. On a lightly floured surface, roll each dough into a 4x6-inch rectangle; then, starting with the longer side, roll up each rectangle tightly, pinching the edges and ends to seal.
Place shaped rolls onto a greased baking sheet. Cover and let rise until doubled again, about 1 more hour. Near the end of the rising time, preheat oven to 400 degrees. With a sharp knife, make a lengthwise slash down the center of each roll and brush or lightly spray with cold water. Bake for 20-25 minutes or until browned. Remove from cookie sheet and cool on a cooling rack.