Preheat oven to 350º
lightly butter an 9x9 baking pan, you can line it with parchment if you like
Toss peaches with cloves, cinnamon, sugar, and cornstarch, and layer in the bottom on a 9x9 inch baking dish, set aside
In a large mixing bowl, combine brown sugar, rolled oats, and flour,
cut the butter into the dry ingredient until crumbly; use two butter knives or a pastry cutter to cut in the butter
Mix in chopped pecans
Layer the topping over the fruit filling in the prepared baking dish
Bake in the center of the oven for about 30 minutes, until golden on top and the peaches are juicy.