In a saucepan combine all of the filling ingredients. Mix well.
Heat the filling on medium high heat. As the cherries thaw, use a spatula to break them up by pressing them into the bottom or side of the pan. Stir the filling to make sure the bottom does not burn. Once the filling is hot and has nice thick consistency, remove from heat and set aside.
Grease a 9 x 13-inch baking dish with butter.
In a bowl mix together all of the bar’s dry ingredients, except for the oats.
Cut the cold butter into small cubes, add into the bowl with the dry ingredients.
Using a pastry cutter, or your fingers, cut the butter into the dry ingredients until it becomes a sandy shaggy texture.
Add in the egg and vanilla, continue to mix with your hands or a pastry cutter until it is fully combined.
Spoon approximately ⅔ of the mixture into the bottom of your greased 9x13 pan.
Gently press the mixture down into the bottom of the pan to create an even, flat, compressed layer of the bar.
Add the oats to the bowl with the remaining bar mixture and mix thoroughly.
Pour the cherry filling over the top of the compressed layer in the pan.
Sprinkle the oat mixture on top of the cherry layer.
Bake at 375 degrees F for approximately 30 to 45 minutes, until the top is golden brown.
Remove from the oven when finished cooking. Let bars cool for at least 15 minutes before cutting.
These bars can be served warm or room temperature, as they are or with ice cream or whipped cream.
Notes
Use cold butter: Cold cubes cut into the flour help create that crumbly texture. Don’t skip the thickening step: Cornstarch gives the filling its jam-like consistency. Line your pan with parchment: This helps with easy removal and cleaner slicing. Cool before cutting: Bars hold together better after they’ve cooled.