Few of us have the time or inclination to make real apple Danish from scratch, but here's a pizza variation that's fast and simple. The crust is just a slab of large, round bakery bread that's been hollowed to create a space for the apple-and-cheese filling.
Using a large serrated knife, slice off the top of the loaf, leaving a bottom disk of bread about 2 inches thick. The part you want is this bottom disk. Score the insides of the disk in a crisscross pattern and remove most of the bread. Heat the oven to 350º.
Melt the butter in a medium-size skillet. Put the bread crust bowl on a baking sheet and brush the melted butter over the insides of the crust, reserving about a tablespoon of butter for cooking the apple slices. Sprinkle the crust with 1 tablespoon of sugar and place it in the oven for 12 minutes.
While the crust heats, make the filling. In a medium-size mixing bowl, cream 1/3 cup of sugar and the cream cheese with an electric mixer. Blend in the egg, yolk, sour cream, vanilla extract, and lemon zest, blending until smooth. Set it aside.
Reheat the butter in the skillet. Add the apple slices and sauté them over moderate heat for about 3 minutes, until soft. Stir in the cinnamon. Remove the crust from the oven after 12 minutes and scrape the apple slices into the crust. Pour the filling over the apple slices and spread it evenly. Bake for 20 to 25 minutes, until the filling looks set and no longer runny. Transfer the pizza to a cooling rack and cool for at least 20 minutes before slicing and serving. Makes 6 servings.