There are as many types of hot cocoa as there are cuisines, so what makes Italy's hot chocolate so decadently delicious? It turns out, it's starch.

9 oz. potato chips (sea-salt flavor works well) 5 tbsp. unsalted butter, melted ¼ cup all-purpose flour 1 ¼ cup heavy cream 10 oz. semisweet chocolate chips 2 large eggs 1 tsp. vanilla extract ...