In a small saucepan, combine the ricotta cheese, almond milk, granulated sugar, vanilla extract, and lemon zest.
Heat the mixture over medium heat, stirring gently until the sugar dissolves and the mixture is smooth and slightly warm (do not boil).
Remove from heat and carefully pour the mixture into individual molds or serving cups.
Allow the panna cotta to cool to room temperature, then cover and refrigerate for at least 4 hours, or until set.
Once set, gently unmold the panna cotta onto serving plates or enjoy directly from the cups.
