2 cups all-purpose flour, sifted
1 tablespoon baking powder
1 teaspoon salt
¼ teaspoon baking soda
¼ cup vegetable oil
¾ cup buttermilk
8 tablespoons butter, softened
¾ cup sugar
1 teaspoon cinnamon
Preheat oven to 400˚. Grease a 9-inch round pan. Combine flour, baking powder, salt, and baking soda in a medium mixing bowl. Stir in vegetable oil. Add buttermilk, and stir just until blended. Knead dough on a lightly floured surface until smooth.
Roll dough into a 15-inch x 8-inch rectangle. Spread butter over the dough.
Combine sugar and cinnamon in a small mixing bowl. Sprinkle over butter. Roll up the rectangle, starting from one long side. Pinch seam to seal. Cut the roll in 1½-inch slices.
Arrange slices, cut side up, in prepared pan.
Bake until lightly browned, 15 to 20 minutes. Remove from oven. Serve hot.