- Beat the butter and cream cheese until smooth. Beat in 2 tsp of the lemon zest and the sugar.
- Add the flour and salt and stir until the dough evenly comes together.
- Shape the dough into two discs, wrap in plastic wrap and chill for at least an hour.
- Preheat the oven to 350°F and line a baking tray with parchment paper.
- Roll out the first disc of dough on a lightly floured surface into a circle about 12 inches across and just shy of 1/4 inch thick. Trim away the rough edges.
- Stir the raspberry jam to soften it and then stir in the remaining 1 tsp of lemon zest. Spread half of the jam over the surface of the dough, right to the edges. Sprinkle half of the white chocolate over the jam.
- Cut the dough into eight wedges and roll up each cookie from the outside edge to its’ point, very much like a croissant, and place the cookies an inch apart on the baking tray. Repeat this with the remaining disc of dough.
- Whisk the egg white until it is very foamy and brush each cookie with it. Sprinkle the cookies generously with sugar.
- Bake the rugelach for 20 to 25 minutes, until they are an even golden color. Let the cookies cool on the tray before removing to store.
The cookies will keep in an airtight container for up to three days.