1 pound bittersweet chocolate, chopped
3/4 cup unsalted butter, at room temperature
3 tbsp instant espresso powder
2 1/2 cups sugar
1/4 cup corn syrup
1 can (12 oz.) evaporated milk
2 cups chopped toasted almonds
Line a 9- by 13-in. pan with foil, letting foil hang over edges. Set aside. In a bowl, combine chocolate, butter, and espresso.
In an 8- to 10-qt. pan, combine sugar, corn syrup, and milk, then bring to a boil over medium heat. Cook, stirring often with a wooden spoon to prevent boiling over, until mixture reaches 235F on a candy thermometer, about 15 minutes.
Remove pan from heat and pour chocolate mixture into hot milk. Stir until smooth. Add almonds, stir just until combined, then pour fudge into prepared pan, smoothing top with spoon. Chill at least 2 hours.