Prepare pan by lining it with aluminum foil and spraying the foil with nonstick cooking spray.
In a small bowl, combine the instant espresso powder and brewed espresso, and stir until dissolved.
Place butter, sugar, heavy cream, and salt in a heavy-bottomed medium saucepan over medium-high heat. Stir until the sugar dissolves and the butter melts.
Continue to cook the fudge, stirring frequently, until it comes to a boil. Once boiling, insert a candy thermometer. Cook the fudge, stirring occasionally, until the thermometer reads 240°F.
Once at 240°F, remove the pan from the heat and add the white chocolate chips and the marshmallow cream. Stir vigorously until the chips and cream are melted and incorporated. If necessary, return the fudge to the heat for brief periods to melt the chips. Add the vanilla and stir it in.
Next, separate into a separate bowl approximately a quarter of the fudge for the white swirl.
Add the reconstituted coffee to the remaining fudge in the pot, and stir until it is well-blended. Scrape the coffee fudge into the prepared pan.
Working quickly, scoop spoonfuls of the white fudge and drop them on top of the coffee fudge in a random pattern, spreading them out evenly over the top. Once all of the white fudge is dotted on top, sprinkle crushed espresso beans all over, then swirl a knife through, creating a pattern of white and brown swirls.
Let the Cappuccino Fudge cool and set completely at room temperature, then overnight in the fridge. Once set, lift it from the pan using the foil as handles and cut it into small squares using a large sharp knife.
Notes
Store Cappuccino Fudge in an airtight container in the refrigerator for up to two weeks, and let it come to room temperature before serving.