Proof is in the... filling. If you’ve ever picked up a box of Bisquick, you’ve likely seen one of its “impossibly easy” recipes printed on the box—dishes ranging from sweet pies to savory casseroles.

It a one-bowl wonder. When I scored the vintage cookbook So Quick with New Bisquick at a thrift store, I was thrilled. The collection of recipes is a goldmine of old-school culinary delights made with ...