Step 1: Preparing the Batter
In a large bowl, cream together softened butter and brown sugar until light and fluffy. Add the egg and vanilla, then mix well.
Step 2: Adding Dry Ingredients
In a separate bowl, combine whole wheat flour, white flour, and baking powder. Gradually add the dry ingredients to the butter mixture, mixing on low speed. Stir in oat flakes with a wooden spoon.
Step 3: Assembling and Baking
Reserve half a cup of the oatmeal mixture. Press the remaining mixture into a buttered 13" x 9" pan. Spread cherry spread over the base, then sprinkle with the reserved oatmeal mixture. Bake at 350°F for about 35 minutes until lightly browned. Cool on a wire rack before cutting into bars.