Preheat oven to 350 degrees F. Spray a 9x13 pan with nonstick cooking spray and set aside.

To make the filling, combine flour and sugar in a medium saucepan. Add the liquid from the cherry cans, setting the cherries aside. Cook over medium heat until the mixture bubbles and thickens to the consistency of pie filling, stirring constantly. Remove from heat and stir in the cherries, vanilla, and red food coloring, if using. Set filling aside.

In a large bowl, combine flour, salt, baking soda, brown sugar, and oats. Cut in the cold butter until particles are the size of small peas. Press half of the oat mixture into the bottom of the prepared pan. Spread cherry filling evenly over the mixture.Cover gently with remaining oatmeal mixture. Smooth with hands so no cherry filling shows through.

Bake for 25-30 minutes or until bars are light golden brown. Remove from oven and let cool to room temperature. Cut into bars and serve.