Impress friends with a rich, buttery Christmas candy that looks like it came from a specialty shop.
Line a 9x5x3-inch loaf pan with foil, extending foil over edges of the pan. Butter the foil; set pan aside.
Butter the sides of a heavy 2-quart saucepan. In the saucepan, combine granulated sugar, brown sugar, half-and-half or light cream, milk, and honey. Cook and stir over medium-high heat until mixture boils and sugars dissolve (about 8 minutes). Clip a candy thermometer to side of pan. Reduce heat to medium-low; continue to boil at a moderate steady rate, stirring frequently, until thermometer registers 234 degrees F, soft-ball stage (15 to 20 minutes). Adjust heat as necessary to maintain a steady boil.
Remove pan from heat. Add butter and vanilla, but do not stir. Cool, without stirring, to 110 degrees F (50 to 60 minutes).
Remove thermometer from pan. Beat mixture vigorously with a clean wooden spoon until fudge just begins to thicken; stir in the 1/2 cup nuts. Continue beating until fudge just starts to lose its gloss (about 10 minutes total).
Immediately spread fudge evenly in prepared pan. Score into 1-1/4-inch squares while warm, and if desired, sprinkle with additional nuts or dried fruit. When fudge is firm, use foil to lift it out of the pan. Cut fudge into squares. Makes 1-1/4 pounds (about 36 pieces).
Store in an airtight container at room temperature for up to 1 week.