Before you start, line your 8x8-inch baking dish with parchment paper, leaving some hanging over the sides to help lift the fudge out later. Get all your ingredients measured and ready.

Start by melting your dark chocolate chips, sweetened condensed milk, and butter together in a medium saucepan. Keep the heat low and stir constantly - this is important to prevent the chocolate from burning. The mixture will be thick and glossy when it's ready.

Take the pan off the heat once everything is melted and smooth. Now stir in your orange extract, fresh orange zest, and salt. Mix until everything is well combined. Take a quick taste and add a bit more orange extract if you want a stronger orange flavor.

Pour the mixture into your lined baking dish. Use your spatula to spread it evenly into the corners. Give the pan a few gentle taps on the counter to remove any air bubbles.

If you want to add toppings, now's the time. You can sprinkle on some extra orange zest, drizzle with melted chocolate, or add a pinch of sea salt - whatever you like!

Put the dish in the refrigerator and let it chill for at least 2 hours, or until the fudge is completely firm. Overnight chilling works great too.

Once the fudge is firm, lift it out of the pan using the parchment paper. Use a sharp knife to cut it into squares. For clean cuts, wipe your knife with a warm, damp cloth between cuts.

Your fudge is ready to serve! Keep it in an airtight container in the fridge for up to 2 weeks. You can also freeze it for up to 3 months - just wrap it well and thaw in the fridge before eating.