This is the easiest fudge we know. It requires no thermometer or special cooling technique; just melt everything together, pour into a pan, and let the mixture cool.

Line an 8-inch square pan with parchment paper or buttered foil that extends over two sides. Place in a heatproof bowl or microwave-safe glass bowl:

Heat over a pan of hot water, stirring until melted, or microwave on high in 30-second increments until melted and smooth, gently stirring after each interval, 1 ½ to 2 ½ minutes total. If desired, stir in:

Transfer the fudge to the prepared pan and smooth the top with an offset spatula, dipping it in hot water as needed. Let stand for at least 1 hour. Remove the fudge from the pan and peel off the foil or parchment paper. Cut the fudge into 1-inch squares and store.