Make a Killer Crumb Cake With Boxed Muffin Mix

Boxed muffin mixes are convenient for baking up a dozen hand-held quick breads, but that’s not all they can do. The pre-packaged mixture contains flour, sugar, flavorings, and a leavening agent, ingredients that are consistent with a number of other cake-like desserts. In fact, with a couple of simple adjustments, you…