Line a 7” x 7” or 8” x 8” mold with wax or parchment paper, leaving excess paper on the sides to remove the fudge.

In a small skillet, toast the pistachios over medium heat just until they feel warm and fragrant, about 5 minutes. You can touch them carefully and when they feel hot, toast them for about 1 more minute. Set aside.

Combine the chocolate chips and condensed milk in a medium saucepan and heat over medium heat. Stir continuously until the chips are quite melted.

Add the extract you are using and the chopped pistachios. Continue stirring continuously until the chocolate is completely melted and looks shiny. If you don't see progress during this point, increase the heat a little for just 30 seconds, while you continue stirring, then return to medium heat until fully melted.

Transfer the fudge to the mold. Use a silicone spatula to spread it well to the corners and edges and level it on top. Let it cool on the counter (not in the refrigerator) for 4 to 6 hours, preferably overnight.

Sprinkle a little cocoa powder over the fudge and sprinkle with finely chopped pistachios.

Cut into equal squares or as desired.