Combine flour, baking powder, salt and baking soda in a medium bowl and
mix well. Stir in vegetable oil. Add buttermilk and stir just until blended.
Knead the dough on a lightly floured surface until smooth. Roll dough into a
15 x 8-inch rectangle.
Heat oven to 400 degrees F. Lightly grease a 9-inch round baking pan.
Spread butter over the dough. Combine the granulated sugar and cinnamon
in a small bowl and mix well. Sprinkle over butter. Roll up rectangle, jellyroll
fashion, starting from one long side. Pinch seam to seal.
Cut the roll into 1 1/2-inch slices. Arrange the slices, cut side up, in
prepared baking pan.
Bake until lightly browned, about 15 to 20 minutes.
Remove from the oven. Pour milk over the top if desired.