Easy Vegan Rocky Road Fudge

1. Line a 9-inch square baking pan with aluminum foil, and coat with cooking spray.
2. Into a medium saucepan, combine sugar, cocoa powder, coconut milk, and salt. Bring to a boil over medium heat, stirring constantly. Once it reaches a boil, stop stirring. Using a candy thermometer, test heat until it reaches the soft ball stage at approximately 235 to 240 degrees.
3. Add butter and vanilla, but do not stir. Allow mixture to cool to 110 degrees, and beat with a spoon or fork for approximately 5 minutes, or until fudge is thick and begins to lose its sheen.
4. Fold in marshmallows and walnuts, and stir for another minute or until mixture starts to become hard to stir. Immediately turn out fudge into baking pan and press to spread evenly to all edges. Cool, slice into 20 squares, and store at room temperature in an airtight container for up to one month.