Preheat the oven to 175 degrees Celsius.
Line a 20*18 baking pan with parchment paper.
Combine the ingredients for the crumble and set aside.
Add two pears to a high speed blender and mix until you have a smooth purée. Don't use too ripe pears, then the bars will become too wet, they should be sweet and juicy but not too ripe. Or skip this step and use more apple sauce, but that will result in bars tasting less like pears.
Combine the wet ingredients in a bowl (first four ingredients).
Next combine the rest of the ingredients (except for the pears) in a separate bowl.
Add the dry ingredients to the wet and mix until fully combined.
Fold in the diced pear gently until fully incorporated.
Add the batter to the lined baking pan and add the crumble on top.
Bake in the oven for 25-35 minutes.
Take out of the oven and let them cool completely before cutting them.