In a saucepan, combine the erythritol, peanut butter, butter, heavy cream, and vanilla extract. Cook over medium-low heat, stirring constantly. Cook until all ingredients are combined and smooth. Do not bring it to a boil.
Step 2
Remove the saucepan from the heat. Let the sauce cool for 10-15 minutes, then transfer it to a glass jar. Let it cool at room temperature until it is warm enough for a sundae but not too hot that it’ll melt the ice cream quickly.
Step 3
To assemble the sundae, add 2 tbsp of the peanut butter fudge sauce to the serving glass/jar. Add 2 scoops of vanilla ice cream. Drizzle with 1 tbsp of fudge sauce. Finish it off with 1 tbsp of whipped cream and 1 tbsp chopped nuts.