Preheat the oven to 375 degrees F. Spray a 9- by 13-inch pan with vegetable oil.
Toss the peach chunks with the schnapps and lemon juice
. Add the peaches
to the pan and spread out evenly. In a medium bowl, mix the oats, sugar
, flour and salt. Add the butter and, using your fingers, rub the butter into the dry ingredients until mixture resembled small walnut-size crumbles. Sprinkle the crumbles evenly over the top of the peaches. Place in the oven and bake 45 minutes. Serve warm, with vanilla ice cream