In a heavy saucepan, combine butter, granulated sugar, and light corn syrup. Cook over medium heat, stirring continuously until bubbling and golden, about 5 minutes.

Continue stirring constantly until it reaches the hard crack stage at 300ºF, about 20-30 minutes; use a candy thermometer for accuracy.

Once at desired temperature, promptly stir in espresso powder, molasses, and chopped pecans.

Carefully pour the hot toffee mixture onto a parchment-lined baking sheet, spreading evenly.

Immediately sprinkle chocolate chips over the hot toffee; let sit for 5 minutes to melt, then spread evenly.

Cool at room temperature for 1-2 hours or refrigerate for 30 minutes to set.

Once hardened, break into large shards and store in an airtight container.