Pre-heat the oven to 180C. Line a 9X13 rectangular tin with parchment paper.
In a large bowl, whisk whole wheat flour and oat flour.
Add honey and mix well.
Use your fingers to incorporate cold butter into the flour. Mix until it comes together when pinched. Divide the dough into 2 parts.
Press one half of the dough into the bottom of the prepared pan. Use your fingers or bottom of a glass to press it down properly.
Bake at 180C for 10-12 minutes until the edges become golden brown.
To make the apple filling, cook all the ingredients in a saucepan set over medium heat until the apples begin to breakdown. The filling should not be runny.
Spread the filling on the baked dough in an even layer.
Crumble the second half of the dough and sprinkle it on the apple filling.
Bake at 180C for 25-30 minutes until the crumble topping is golden brown.
Let the bars cool completely before slicing them.
Recipe by Bake with Shivesh at https://bakewithshivesh.com/oat-apple-crumble-bars/