Prepare crust: In a bowl, mix almond flour, melted butter, erythritol, and salt until crumbly.
Press and chill: Press mixture into a 9-inch springform pan and refrigerate for 15–20 minutes (or bake at 350°F for 8–10 minutes if preferred).
Make filling: Beat softened cream cheese, peanut butter, erythritol, and vanilla until smooth.
Whip cream: In a separate bowl, whip heavy cream until soft peaks form, then fold into the peanut butter mixture.
Assemble: Spread filling over the crust and smooth the top.
Chill: Refrigerate for at least 4 hours (overnight for best texture).
Serve: Garnish with whipped cream, chocolate drizzle, or chopped peanuts before serving.