Preheat the oven to 325°F (163°C) and line 16 standard muffin cups with paper liners.

In a medium bowl, sift together the flour, baking powder, and baking soda. Add in half of the granulated sugar along with all of the salt, and whisk to combine evenly.

In a separate small bowl, whisk together the eggs, egg yolk, oil, the remaining ½ cup of sugar, melted butter, lemon zest, and vanilla extract until the mixture is light and frothy. Gently whisk in half of the dry flour mixture, followed by half of the milk. Add the remaining flour mixture, then the rest of the milk, mixing gently after each addition. Be careful not to overmix the batter.

Divide the batter evenly among the prepared muffin cups. Bake for 18 to 22 minutes, or until a toothpick or cake tester inserted into the center comes out clean. Allow the cupcakes to cool in the pan for 5 minutes, then transfer them to a wire rack to cool completely.

To make the frosting, beat the softened cream cheese until smooth and creamy. Add 2 tablespoons of cream and continue beating until completely smooth with no lumps. Slowly pour in the remaining cream and beat until soft peaks form. Gradually add the sugar, beating until the frosting thickens to a spreadable consistency. Finally, mix in the lemon juice.

Once the cupcakes are completely cooled, spread the cream cheese frosting generously over the tops. Finish with a small dollop of Small Batch Lemon Curd for a bright, tangy touch.