Preheat oven to 350°F. Line an 8x8 pan with foil, leaving a 2-inch overhang along the sides.
First prepare the recipe for Small Batch Lemon Curd and let it cool and set in the fridge until thoroughly chilled.
For the crust, combine flour, brown sugar and salt in a medium bowl so there are no lumps of sugar left. Add melted butter and mix until evenly combined and it looks like damp sand. Press the mixture evenly into the bottom of the prepared pan and bake for 10-12 minutes until lightly golden. Set aside to cool slightly while you prepare the filling.
Reduce oven temperature to 325°F.
For the filling, beat cream cheese in a medium bowl until smooth. Add the sugar and lemon zest and beat until smooth using an electric hand mixer. Beat in egg until well incorporated and then mix in yogurt and vanilla. Pour the mixture over the crust and spread it out evenly.
Dollop teaspoons of lemon curd over the surface and swirl it through with a butter knife. Bake for 20-25 minutes until the edges are set and the middle has a slight wobble. Transfer to a wire rack to cool completely and then refrigerate for at least 2 hours before slicing. Enjoy!