Line unbaked, unpricked pastry shell with foil; fill with pie weights or dried beans. Bake at 450° for 5 minutes; remove weights and foil; bake for 5 to 7 minutes longer, until almost done. Remove from oven.
Reduce oven to 425°.
Combine mashed potatoes, half-and-half and butter, set aside.
In a mixing bowl, combine cottage cheese, sour cream, eggs, salt, garlic powder, cayenne pepper and black pepper; beat with electric mixer on high speed until smooth.
Add potato mixture; beat 1 minute longer. Stir in shredded cheese, chopped onion and bacon. Pour potato mixture into warm pastry shell.
Bake at 425° for 35 to 40 minutes or until golden brown.