In a small bowl, combine milk and gelatin powder. Stir and set aside.
In a medium saucepan set to medium heat, bring heavy cream and sugar to a boil, watching carefully, as the cream will quickly bubble up. Stir in gelatin mixture until completely dissolved. Cook for 1 minute, stirring constantly. Remove from heat. Stir in vanilla and lemon extracts. Pour into four individual ramekin dishes.
Cool ramekins uncovered at room temperature. Once cool, cover with plastic wrap and refrigerate for at least 4 hours (but preferably overnight) before serving.