Spray or brush cooking oil into an 8x8-inch baking pan and line with parchment paper, being sure to leave overhang on all sides.
In a medium heatproof bowl set over a pan of simmering water (or in a double boiler), add butter, both kinds of chocolate chips, sweetened condensed milk, gingerbread extract, and salt.
Stir the mixture until chocolate is completely melted. Mixture should be warm, but not hot.
Remove from heat and pour mixture into prepared baking pan. Smooth top.
Place caramel bits and cream in a small heatproof bowl and microwave for one minute at 50% power. Stir mixture. Repeat until caramel is completely melted.
Drizzle caramel over the top of the fudge in the pan and using a knife, swirl.
Sprinkle on edible gold stars, sprinkles, or other decoration if desired.
Refrigerate fudge for at least 2 hours, until completely set.
Remove fudge from pan and cut into squares of desired size.