Heat heavy cream and almond milk in a saucepan over medium heat until warm (do not boil).
In a bowl, whisk egg yolks and powdered erythritol until pale and slightly thick.
Slowly add warm cream mixture to the egg mixture while whisking continuously.
Pour mixture back into the saucepan and cook on low heat, stirring until thickened.
Remove from heat and stir in vanilla extract and salt.
For baked custard, pour into ramekins and bake in a water bath at 160°C (325°F) for 30–35 minutes.
For no-bake version, dissolve gelatin in water, mix into custard, and refrigerate until set.
Cool slightly and chill before serving or serve warm.
