Combine all of the ingredients in a mixing bowl and stir until smooth. Line an 8-inch square pan with parchment paper and pour the mixture into the bottom, using a spatula to smooth the top.
Place the fudge in the freezer to set until firm, about 1 hour.
Slice into small squares and store the fudge in an airtight container in the freezer. Serve it directly from the freezer, as it will melt very quickly at room temperature!