Grandma Doris always called this her 4 ingredient sweet and salty secret. I finally learned her trick and the pan disappears from the picnic table in

spread and swirl the melted chocolate over the caramel. You can create simple waves or more dramatic swirls—this is where the bars get their pretty picnic-table look.

Allow the bars to cool at room temperature until the dish is no longer hot, then transfer to the refrigerator and chill for at least 1–2 hours, or until the caramel and chocolate are fully set. This step makes slicing much neater.

When ready to serve, remove the dish from the refrigerator and let