Preheat oven to 400°
In a large mixing bowl, whisk together flour and brown sugar. Add 1 cup of butter and mix on low speed until crumbly.
In a medium bowl, whisk sugar, salt, nutmeg and cinnamon together and set aside.
Peel, core and slice apples and pears. Put in a large bowl, add walnuts.
Mix in sugar mixture and stir until all fruit and walnuts are coated well.
Pour fruit mixture into a 9 x 13 inch baking dish.
Add the remaining 1/4 cup butter (sliced) and just place on top of the fruit mixture randomly.
Add the flour mixture on top of fruit and spread evenly.
Bake uncovered at 400° for 40-50 minutes.
Serve warm with ice cream or whipped cream.