For the ice cream, set a bowl over an ice bath and set aside.
Combine cream, almond milk and sweetener in medium saucepan over medium heat. Stir until sweetener dissolves and mixture reaches 175F on an instant read thermometer.
Whisk egg yolks in a medium bowl. Slowly add about 1 cup of the hot cream mixture, whisking continuously, to temper the yolks. Then slowly whisk egg yolk mixture back into cream, whisking continuously.
Cook until mixture reaches 180F on an instant read thermometer. Remove from heat and whisk in peanut butter until well combined.
Pour mixture into bowl set over ice bath and allow to cool 10 minutes. Then wrap tightly in plastic wrap and chill at least 3 hours.
Stir in vodka, if using, and vanilla extract. Sprinkle with xanthan gum and whisk vigorously to combine. Pour custard into the canister of an ice cream maker and churn according to manufacturer's directions.
Meanwhile, make the fudge sauce. In a small saucepan over medium heat, whisk together whipping cream and sweetener until combined. Bring to a simmer and remove from heat.
Add chopped chocolate and let sit 5 minutes, until chocolate is completely melted. Add vanilla extract and whisk until smooth. Let cool at least 10 minutes.
Once the ice cream is churned, transfer half to an airtight container. Dab spoonfuls of sauce over the ice cream and swirl to combine. Repeat with remaining ice cream and remaining sauce. Cover and freeze at least one hour until firm.