Preheat and Prepare: Preheat your oven to 350°F (175°C). Grease a 9×13-inch baking pan and set aside.
Mix Wet Ingredients: In a large mixing bowl, cream together the softened butter and brown sugar until light and fluffy. Add the egg and vanilla extract, mixing well after each addition.
Combine Dry Ingredients: In a separate bowl, whisk together the whole wheat flour, white flour, baking powder, and oat flakes.
Combine and Form Dough: Gradually add the dry ingredients to the wet mixture, stirring until just combined. The dough will be crumbly.
Press into Pan: Press two-thirds of the dough mixture evenly into the prepared baking pan to form the bottom crust.
Spread Cherry Filling: Spread the cherry spread evenly over the dough in the pan.
Create Top Crust: Sprinkle the remaining dough mixture evenly over the cherry filling, pressing down lightly.
Bake: Place the pan in the preheated oven and bake for 25-30 minutes, or until the top is golden brown.
Cool and Serve: Allow the bars to cool completely in the pan on a wire rack before cutting into squares and serving.
