Preheat oven to 375 degrees. Wash blueberries and remove any stems. Place in shallow baking dish and sprinkle with lemon juice and spices. Cut butter into flour with knife, rub with fingertips until mixture resembles crumbs and stir in sugar. Spread mixture over blueberries and bake in preheated oven for 40 minutes or until topping is crisp and brown. Serve hot or cold with sour cream.