Created by Miss-Missey on June 9, 2012
Step 1: Preheat oven to 350 degrees. In a medium bowl, combine the flour, sugar, baking powder, and salt.
Step 2: Beat in the milk and oil. Spread mixture in an ungreased 8x8-inch baking dish. Layer the halved plums on top.
Step 3: Whisk together the brown sugar and cinnamon and sprinkle over the plum-topped batter. Pour the boiling water over everything!
Step 4: Bake at 350 degrees for 1 hour, until cake is browned on top. (The top layer should test done with a fork with only a few crumbs, if you're unsure.)