Preheat your oven to 350F and set aside 4 12 ounce oven safe jars. Feel free to also use an 8×8″ baking dish if desired.
Add all of the filling ingredients into a medium bowl and mix to combine. Transfer the filling into the jars.
In the same bowl, add the oats, walnuts, coconut sugar, cinnamon, and salt and mix to combine. Lastly, add in the coconut oil and mix until evenly distributed. Top over the apples.
Place the crumbles into the oven for 25-30 minutes or until the apples are soft and the tops turn golden brown.
Remove from the oven and let cool for 30 minutes before serving.
Once cool, dollop with greek yogurt. Store extras in the fridge for up to 5 days and enjoy cold or warm.