A mix of beef, pork, and bacon ensures meatiness. Worcestershire sauce, chopped prunes, and cider vinegar add balance and occasional suggestions of sweetness.
The toasted crumbs on top have a cheesy crispness, and the pasta beneath is creamy and rich. Kids will appreciate the individual servings, but the recipe makes plenty, so why not pour the extra into a baking...
The generally accepted legend of whoopie pies is that they evolved from little cakes mothers would make their children from leftover cake batter and frosting.