Line an 8-inch square baking pan with lightly-greased parchment paper or non-stick foil. Set aside.
Place the chocolate chips in a microwave-safe bowl. Microwave at 70 percent power for 90 seconds. Stir, using the residual heat to fully melt the chocolate chips. If needed, microwave for additional 15 second intervals.
Stir the sweetened condensed milk into the melted chocolate until smooth. If desired, stir in a pinch of salt.NEXT STEP