Candied Orange Ice Cream with Chocolate Fudge Swirl

Prepare Candied Orange Peel:

Drain about 10 ounces of candied orange peel in syrup, separating the syrup from the solid peel.
Spread pieces of peel out on a sheet of parchment paper or a silicone baking mat and let dry out for a day or so.
Once dried, chop into 1/4-inch pieces and toss with granulated sugar to keep the bits from sticking together (if using already dried candied orange peel, skip this step and just chop it).
Make Ice Cream Base:

In a medium saucepan, combine milk, 1/2 cup of cream (keep remaining 1 cup heavy cream in the refrigerator for later), and strained orange syrup and salt.
Place saucepan over medium heat and warm until it starts to steam and bubble around the edges, but don’t let it fully boil.
Meanwhile, whisk egg yolks in a bowl until smooth and one shade lighter in color.
Slowly ladle hot milk mixture into the egg yolks, 1/4 cup at a time, whisking continuously, until about half of the milk mixture has been incorporated and egg yolk mixture is hot to the touch.
Pour egg yolk mixture into saucepan with remaining milk; reduce heat to low and cook, stirring occasionally, until slightly thickened and mixture reaches 170 degrees F on an instant read thermometer.
Remove from heat and pour through a fine mesh sieve into a heat-proof bowl.
Whisk together 1 tablespoon granulated sugar with powdered guar gum in a small bowl. Whisk in 1 tablespoon of cold cream until evenly dissolved, then stir into warm ice cream base along with the rest of the reserved heavy cream and orange extract (if using).
Press a piece of plastic wrap onto the surface of the cream to prevent a skin from forming, then refrigerate for at least 4 hours or overnight until completely chilled through (the colder the ice cream base is, the more quickly it will churn).
Prepare Fudge Swirl:

In a saucepan, combine sugar, cream, cocoa powder (sifted if clumpy), corn syrup, and salt. If you have any candied orange syrup left, you can use it in place of some of the corn syrup.
Stir over medium heat until sugar is dissolved and mixture just starts to bubble. Remove from heat and add chopped chocolate, gently stirring until completely melted and smooth.
Let cool for 15 minutes, then transfer to a piping bag or a zip-top plastic bag. Refrigerate for about 30 minutes or let sit at cool room temperature for an hour or two until ready to use. If fudge was chilled for longer, let it warm up to room temperature for an hour or so before swirling. Cut off the corner of the bag or fit with a 1/4-inch piping tip.
Churn Ice Cream:

Pour chilled ice cream base into ice cream machine and churn according to manufacturer’s instructions.
Have a shallow, long container (like a loaf pan), pre-chilling in the freezer while your ice cream churns.
Once ice cream reaches the consistency of soft serve, spoon a bit into your chilled container, spreading it out into an even layer. Sprinkle with candied orange bits (smush them a bit to mix up with the cream), and squeeze a squiggle of fudge over top. Repeat with additional layers of ice cream, orange bits, and fudge, until container is filled and all of the ice cream has been used. End with a final sprinkle of candied orange and a drizzle of fudge, then place container in the freezer to freeze overnight until solid.
If storing in the freezer for more than a few days, press a piece of parchment paper onto the surface of the ice cream or cover the container with a lid to prevent freezer burn. With the guar gum, the ice cream will keep quite well for about a month.