My mother-in-law demands I bring these 3 ingredient treats to every family gathering. The pan is always scraped completely clean before dinner is even over.

You can swap the strawberry pie filling for other canned pie fillings you enjoy, such as cherry, blueberry, or apple, while keeping the yellow cake mix and butter the same. For a slightly richer flavor, use browned butter (melt the butter and cook it a bit longer until it turns golden and smells nutty, then cool slightly before mixing with the cake mix). If you like a little texture, stir 1/2 cup of chopped nuts (such as pecans or walnuts) into the reserved crumb mixture before sprinkling it over the top. You can also add a pinch of cinnamon to the crumb mixture for a warm, homey note, especially if you use apple or cherry filling. For smaller households, you can halve the recipe and bake it in an 8×8-inch or 9×9-inch pan; start checking for doneness around 22–25 minutes. Food safety tips: Always make sure the bars are baked until the filling is visibly bubbling, which ensures they are heated through properly. Let the bars cool before covering to avoid condensation, which can make the topping soggy. Store leftovers, covered, at room temperature for up to 2 days, or in the refrigerator for up to 4 days. If using dairy-based toppings like whipped cream or ice cream, add them only to individual servings and return any leftovers promptly to the refrigerator or freezer.