Pour milk into a large liquid measuring cup. Add lemon juice and zest. Stir to combine and set aside for 3-5 minutes, to allow the milk to curdle slightly.
In a large bowl, whisk together flour, sugar, baking soda and salt. Set aside.
In a separate large bowl, whisk together eggs, melted butter, ricotta, vanilla extract and milk mixture, whisking until well combined.
Using an ice cream scoop or ¼ cup measuring cup, scoop muffin batter into prepared muffin tin, filling the muffin cups about 2/3rd’s of the way full.
In a small bowl, stir together granulated sugar and lemon zest to form lemon sugar topping. Sprinkle muffin batter in muffin tin with prepared lemon sugar topping.
Recipe adapted from I Heart Eating