- 1/4 cup butter
- 3/4 cup all-purpose flour
- 1/3 cup white sugar
- 1/3 cup chopped walnuts (optional)
- 1/4 cup rolled oats
- 1 tablespoon ground cinnamon
- 1 teaspoon baking powder
- 1/4 teaspoon salt
- 1 cup milk
- 1 teaspoon vanilla extract
- 3 cups sliced fresh plums
- 1/2 teaspoon ground cinnamon
- Preheat oven to 350 degrees F (175 degrees C).
- Set butter in the middle of an 8-inch baking pan.
- Heat butter in the pan in the preheated oven until butter melts, about 2 minutes.
- Whisk flour, sugar, walnuts, oats, 1 tablespoon cinnamon, baking powder, and salt together in a bowl. Add milk and vanilla; stir well to create a batter.
- Pour batter into baking pan over melted butter. Place sliced plums over batter into baking pan. Sprinkle top with 1/2 teaspoon cinnamon.
- Bake in the preheated oven until batter browns, fruit bubbles, and a knife inserted into the batter comes out clean, 45 to 50 minutes. Cool to room temperature.