This sour cream blueberry crumb cake recipe is perfect for those who want a rich and creamy dessert. The cake is made with sour cream, which gives it a moist and tangy flavor. The blueberry filling is made with fresh or frozen blueberries, lemon juice, and sugar, which gives it a tangy and sweet taste. The crumb topping is made with butter, flour, and sugar, which gives it a crunchy texture. This recipe is easy to make and can be served warm or cold, with a dollop of whipped cream or a scoop of vanilla ice cream.