Preheat the oven to 350° and prepare an 8x8 baking pan with non-stick spray and/or parchment paper.
Combine all ingredients for the cherry filling in a bowl and stir together gently to combine. Place in refrigerator until ready to build bars.
In another bowl place the flour, oats, brown sugar, baking soda, nutmeg, cinnamon and salt. Stir together to combine everything evenly. Add the melted butter a little at a time to combine completely with flour mixture.
Take ⅓ of the crumble mixture and place it in the bottom of the prepared pan. Evenly spread out along the bottom and gently press with fingers to create an even crust. Bake bottom crust for 12 minutes, remove and cool for at least 10 minutes.
Once the crust bottom crust is cooled, take the cherry mixture out of the fridge and evenly distribute it on the baked bottom. Sprinkle the reserved crumble mixture over the top of cherries and gently press down to pack in crumble top.
Bake again for 25 minutes, the topping will brown slightly, but not much. Remove from oven and cool. You can enjoy warm which is delicious and crumbly. Or, you can enjoy refrigerated or cooled which is also delicious and more bar-like. I enjoyed my second helping the next day my with my morning coffee straight out of the fridge and it was heaven!