These little cookies melt in your mouth like a peanut-butter cup meringue. This winning recipe started as a failed recipe for chocolate meringues. Cocoa caused the peaked meringues to sink into disks while baking. The disks looked pretty sad on their own, but make perfect tops and bottoms for sandwich cookies. The combination of salty, creamy peanut butter with crisp, airy cocoa meringue makes for a dessert everyone will ask for. Get the recipe below.