Beat 1/2 cup butter or margarine until smooth. Add 1/4 cup white sugar and 1/2 cup brown sugar and beat well. Add egg, milk, peanut butter and vanilla and beat well. Stir in 1 cup flour, 1 cup oats, and 1/2 teaspoon baking soda.
Spread in a greased 13 x 9 inch pan. Spread preserves all over top. Sprinkle with crumb topping.
To Make Topping: Mix together 1/2 cup flour, 1/2 cup quick oats, 1/4 cup brown sugar, 1/8 teaspoon baking soda, and 3 tablespoons softened butter or margarine until crumbly. Sprinkle over the top of the preserves.
Bake at 350 degrees F (175 degrees C) for 18 – 20 minutes.