To prepare a surprise apple cake baked goods recipe, first preheat oven to 350?F (180?C) and grease and flour two 8-inch round cake pans. In another large bowl, combine the flour, baking powder, sugar, cinnamon, and salt. Gradually add the wet ingredients to the dry ingredients, mixing well after each addition. Pour the batter into the prepared pan and bake for 35 to 40 minutes, or until toothpick inserted in the center comes out clean. Let cool in pan for 10 minutes before removing to wire rack to cool completely.