Melt chocolate morsels and sweetened condensed milk using double boiler method or very low heat. If you don’t have a double boiler, you can use a smaller pot sitting down inside of a larger pot with water in it to safely melt too. Stir continuously until chocolate melts and mixture becomes smooth and glossy. Add the vanilla and pecans if desired then stir until glossy and smooth again. Line an 8×8 baking dish with parchment paper. Pour mixture into baking dish and smooth out. Cool completely and cut into squares. Enjoy!