In a medium bowl combine diced apples and pear with lemon juice, lemon zest, apple pie spice, granulated sugar, and 4 teaspoons flour. Stir well to combine. Set aside.
In a medium bowl combine, all topping ingredients except butter. Whisk to combine.
Using a pastry cutter, or your fingers, cut in cold, cubed butter until mixture comes together and the oats hold in clumps. Set aside
Prepare 2 mini cocottes or other 12-ounce ovenproof baking dishes by greasing with softened butter, set aside.
Preheat oven to 350 degrees F.
Divide apple and pear mixture between the 2 cocottes. It's ok if it's overflowing a bit.
Top with oat mixture, dividing evenly between cocottes. This too will be overflowing, just pat it down a bit.
Bake at 350 degrees F for about 40 minutes until topping is brown and the mixture is a bit bubbly.
Remove from the oven and let sit for about 10 minutes before serving. Top with a scoop of ice cream or fresh whipped cream for serving, if desired.