Lemon Blueberry Bars make are filled with a sweet and juicy blueberry & lemon filling. This simple recipe, the buttery oatmeal streusel crust doubles as the topping. Yields 9-12 thick barsLemon Blueberry Crumble BarsLemon Blueberry Crumble Bars make the perfect easy summer treat. Filled with a sweet and juicy blueberry & lemon filling. Best of all…