Combine the first five ingredients in a work bowl. Add the butter, and working with two knives or a pastry cutter, shred the it into small rice-sized granules. Mix in the rolled oats by hand (mixing in by hand helps retain the texture or oatmeal).
Place apples in a greased 8 or 9 inch square pan. Drizzle bourbon over apples, if desired. Spoon flour mixture evenly over the apples.
Bake in a preheated 375 degree oven 40-45 minutes until browned.
Serve warm with ice cream or whipped cream.
Makes 6-8 servings.