Preheat oven to 350F.
Combine oats, flour, maple syrup, brown sugar, cinnamon, melted coconut oil, and salt in a medium bowl. Mix until well combined.
Add muffin liners to a muffin pan. SPRAY THE MUFFIN LINERS WITH NON-STICK SPRAY (This is crucial because the mixture may stick without it). Spoon ~2 heaping tablespoon of oat mixture into each cup, filling it up about halfway and making a little cup by pressing up the edges. Press it down as firmly as you can. Repeat in ~8 cups. Cook oat cup for 16-18 min until they are golden on the edges.
Meanwhile, dice apple into small pieces. In a medium pan, warm coconut oil and add apples and cinnamon. Cook apples on low-medium heat for 4-5 minutes until softened. (Don't overcook or they will become mushy when cooked in the oven).
Add a spoonful of apple mixture on top of each oat cup, pressing down slightly. Bake for another 5 minutes.
Allow apple crisp bites to cool completely before removing from wrapper. If you try to open them when they are still warm they will likely crumble.
Store in the fridge in their cupcake linings to keep shape and last longer.
Optional: Add some vanilla ice cream on top!