In a bowl, stir together cream cheese, sugar, vanilla, lemon juice & lemon zest until well combined. Transfer mixture to piping bag and refrigerate. Combine chocolate chips and vegetable oil in microwave safe bowl. Microwave for 30 second intervals, stirring between, until chocolate is fully melted & smooth. Line a mini muffin pan with paper candy cups. Spoon 1 tsp of melted chocolate into each up, tap pan on counter so chocolate flattens out. Refrigerate pan for 15 minutes. Remove pan and piping bag from fridge. Pipe a portion of the cheesecake mixture into the centre of each cup, then top with another 1-2 tsp of melted chocolate. Sprinkle the tops of each cup with sea salt, then return to fridge for 20 minutes, or until chocolate has fully hardened.