HIGH for 2 to 2 1/2 hours, or on LOW for 3 1/2 to 4 hours, until the blueberries are bubbling around the edges and the cake mix on top looks set and mostly cooked through. The center may be a little softer and more spoon-cake-like, which is perfect for this style of dessert.
Turn off the slow cooker and let the dump cake sit, covered, for about 10 to 15 minutes to thicken slightly. This rest time helps the hot fruit settle and makes it easier to
