Preheat oven to 325 degrees. In a mixing bowl, using an electric hand mixer on medium speed, whip together cream cheese and 1/3 cup granulated sugar until fluffy and smooth, about 2 minutes. Stir in sour cream and heavy cream. Add in egg yolk, 1 Tbsp lemon juice and 1 tsp lemon zest and mix until combine, set aside.
In a separate mixing bowl, whisk together flour, baking powder, baking soda and salt, set aside. In another mixing bowl, using an electric mixer, whip together butter and 2/3 cup granulated sugar until pale and fluffy. Stir in egg. Mix in sour cream, lemon juice, lemon zest and vanilla extract. Add in dry ingredients and mix just until combine. Pour cake batter into a buttered 9 inch springform pan and spread mixture into an even layer. Pour cream cheese mixture over cake batter layer and spread cream cheese mixture into an even layer (you don't need to swirl the cake, it did it on it's own while baking). Bake in preheated oven for 35 - 40 minutes until edges are golden and toothpick inserted into center comes out clean. Allow to cool before cutting into slices.
I tried serving and eating this a few different ways:
1. Serve warm garnished with lots of powdered sugar
2. Allow to cool at room temperature 30 minutes, then cover and chill 1 hour. Slice and serve with sweetened whipped cream and optional fresh raspberries.
3. Allow to cool at room temperature 30 minutes, then cover and chill 1 hour. Slice and serve with raspberry sauce and sweetened whipped cream.