Preheat the Oven: Start by preheating your oven to 350°F (180°C). Grease a muffin tin and, if you prefer, line it with muffin liners for easier removal.
Mix the Ingredients: In a bowl, whisk together the sweetened condensed milk, lemon juice, eggs, melted butter, self-rising flour, vanilla extract, and lemon zest until the mixture is smooth.
Fill the Muffin Tin: Pour the lemon mixture evenly into the prepared muffin tin, filling each cup about three-quarters full.
Bake: Place the muffin tin in the preheated oven and bake for 18-20 minutes until the tops are golden and the centers are set.
Cool and Serve: Allow the pies to cool in the tin before dusting with powdered sugar for that delightful finishing touch. Serve and enjoy your delicious Baby Lemon Pies!