In a medium mixing bowl, blend 8 oz of softened cream cheese, 1/4 cup granulated sugar, and 1 tsp vanilla extract until creamy, about 2-3 minutes.

In a large bowl, whisk together 1.5 cups all-purpose flour, 1.5 tsp baking powder, 0.5 tsp baking soda, and 0.5 tsp salt until evenly mixed.

Beat 0.5 cup unsalted butter and 1 cup granulated sugar in a bowl until fluffy, about 3-4 minutes. Add in 2 large eggs one at a time.

Stir in 1 tsp vanilla extract, 0.25 cup fresh lemon juice, and the zest of 1 lemon into the butter mixture. Fold in 0.5 cup sour cream and 0.25 cup milk.

Gradually add the dry ingredients to the wet ingredients, mixing gently until just combined.

Spoon 1 tablespoon of batter into each lined muffin tin, add 1 teaspoon of cheesecake filling, then cover with another tablespoon of batter.

Preheat your oven to 350°F (175°C) and bake for 18-22 minutes until golden and a toothpick comes out clean.

Cool the muffins in the tin for about 10 minutes, then transfer to a wire rack.

To make the lemon frosting, beat 0.5 cup softened butter, add 2 cups powdered sugar and 2 tbsp fresh lemon juice until smooth.

Frost each cooled cupcake generously with the lemon frosting, adding lemon zest or slices on top.