1. 1. Line a baking sheet with parchment paper or a silicone baking mat.

2. 2. In a medium saucepan, combine the butter, sugar, and corn syrup. Cook over medium heat, stirring constantly, until the mixture reaches 300°F on a candy thermometer.

3. 3. Remove the pan from the heat and quickly stir in the espresso powder, vanilla, and salt. Pour the hot toffee onto the prepared baking sheet, spreading it into an even layer.

4. 4. Sprinkle the chopped pecans evenly over the toffee. Allow to cool completely, about 30 minutes.

5. 5. Once cooled, melt the chocolate in a double boiler or in the microwave, stirring frequently until smooth. Drizzle the melted chocolate over the toffee and pecans.

6. 6. Let the chocolate set, about 20 minutes, before breaking the toffee into bite-sized pieces.