To make the sponge: Pour the starter into a mixing bowl. Stir the milk and olive oil into the starter. Blend in the flour and sugar to make a fairly stiff sponge. Cover the bowl and let it stand at room temperature overnight.
The dough: Blend 1/2 cup of the flour with the salt and baking soda and stir into the sponge to make a fairly slack dough.
Using the remaining 1/2 cup of flour, make sure the kneading surface is well floured before you turn it out. Flour your hands and knead for 2 to 3 minutes enough to make the dough cohesive. Sprinkle flour on any sticky spots.
Prepare the pans: Use one 9 x 11-inch baking pan. Grease the sides well.
Melt 1/4 cup of the butter and spread in pans. Sprinkle 1/4 cup of the sugar over the butter, then sprinkle with the cinnamon. Roll out the dough with a well-floured rolling pin until it's about 12 x 18 inches. (While rolling, sprinkle flour on any sticky spots, either on top of or under the dough.) Spread the remaining butter over the dough, then spread the remaining brown sugar over the butter. You can also use nuts/raisins just spread them evenly over the brown sugar. Starting at the long edge, roll the dough up, jellyroll style. Seal the edges. Cut the roll into 3/4- to 1-inch slices and arrange them in the prepared pan. Cover the pans and let the dough rise for about 1 hour.
Heat oven to 400 degrees F.
Bake the rolls for 15 minutes, then turn the heat down to 350 degrees F and continue baking for about another 20 minutes. Rotate the pan halfway through baking to insure even browning. Remove the buns from the oven, place a serving plate over each pan and invert the buns onto the plate. Leave the pan in place until the buns are securely on the plate, topping and all. Serve warm if possible.