In a large bowl, combine the flour, butter, cream cheese, and sugar. Mix until the dough comes together.
Divide the dough into four equal pieces. Wrap each in plastic wrap and refrigerate for at least one hour.
Preheat your oven to 350°F (175°C).
Roll out each piece of dough on a floured surface into a circle. Spread a thin layer of jam over the dough, then sprinkle with walnuts and cinnamon.
Cut the dough into 12 wedges. Roll each wedge, starting from the wide end, to form a crescent shape.
Place the rugelach on a parchment-lined baking sheet. Brush with egg wash.
Bake for 20-25 minutes, or until golden brown. Let cool before serving.