Over medium heat, melt butter in medium saucepan. Cook butter until golden brown, about 1 - 2 minutes.
Stir in cream and bring to a simmer over medium-low heat.
Reduce heat to low and add erythritol and salt. Stir until completely dissolved.
In a small bowl, mix xanthan gum with 2 tablespoons hot cream mixture. Stir with fork until xanthan gum is dissolved. Mixture will be thick. Add to cream mixture and stir until combined.
In a small bowl, whisk eggs. Continuing to whisk, add 2 tablespoons of hot cream mixture into bowl with eggs. Repeat several times, adding 2 tablespoons of cream mixture at a time until eggs are tempered (warm). Slowly add tempered eggs to cream mixture in saucepan, whisking to combine.
Continue to stir, over low heat, until mixture thickens and coats the back of the spoon. Egg safe temperature is (160°F.) Remove from heat.
Pour into a container and cool in the refrigerator for 2 - 3 hours, depending on your refrigerator temperature.
While mixture is cooling, toast your almonds: In a medium skillet over medium heat, melt 1 tbsp butter (optional) and cook almonds until fragrant and starting to brown, about 3 - 5 minutes. Remove from the heat and transfer to a plate to cool. Cool completely before using.
Remove chilled mix from refrigerator and stir in maple extract and vodka.
*If using an ice cream maker - Pour into ice cream maker and follow manufacturers instructions.
**If using freezer - pour chilled custard into mixing bowl and whip for 3 - 5 minutes to add air and increase volume of mixture. Fold in almonds and transfer mixture to an 8 x 5 loaf pan. Cover by laying plastic wrap directly on surface and then wrapping the plastic around the pan. Freeze for at least 2 - 3 hours.
Serve sprinkled with extra toasted almonds and a spoonful of sugar-free maple syrup on top.
Set solidly frozen ice cream on counter for 15 minutes to soften before scooping.