This sour cream blueberry crumb cake recipe is perfect for those who love a tangy and creamy taste. The cake is made with sour cream, giving it a moist and fluffy texture. The blueberry filling is made with fresh or frozen blueberries, lemon juice, and sugar, giving it a sweet and tangy taste. The crumb topping is made with flour, sugar, and butter, making it crunchy and delicious.