1. Prepare the Crust:

1. Preheat oven to 350°F (175°C). Line a muffin tin with paper liners.
2. In a large bowl, cream together butter and granulated sugar until light and fluffy. Beat in eggs one at a time, then stir in vanilla extract, lemon juice, and lemon zest.
3. In a separate bowl, whisk together flour, baking powder, and salt. Gradually add to the butter mixture, alternating with milk, until just combined. Do not overmix.
4. In a small bowl, beat together cream cheese, powdered sugar, and 1/2 teaspoon vanilla extract until smooth.
5. Fill each muffin cup half full with batter. Add a spoonful of cream cheese mixture in the center, then top with remaining batter to cover.
6. Bake for 18-20 minutes, or until a toothpick inserted into the muffin part comes out clean. Cool in pan for 5 minutes, then transfer to a wire rack to cool completely.