With a stand or hand mixer with beater attachment, cream together butter, 1 package cream cheese and sugar just until light and fluffy, about 1 minute. Then add in sour cream, vanilla and salt and combine. Lastly, add in flour and cocoa powder and mix just until combined.

Lightly flour a clean surface and dump dough onto the surface. Divide the dough into four equal sized balls (I use a scale) and flatten each into a disk. Dough should be a little sticky. Wrap each disk in saran wrap and chill for two hours or overnight. It also freezes well for up to 2 months.

Divide the dough into four balls. Wrap in saran wrap and chill for two hours or overnight.

When ready to bake, pre heat oven to 350 F.

Combine 1 package room temperature cream cheese with powdered sugar.

Roll out each ball on a lightly floured surface into a 9-inch diameter circle about 1/8 inch thick , keeping the other balls in the fridge until you are ready for them. Make sure to use enough flour to prevent sticking.

Spread a thin layer of cream cheese on the circle, sprinkle evenly with sugar.

Cut the circle into 12 triangles. Roll up each triangle from the wide end, and secure the tip into the cookie so you have a little spiral. Repeat with other balls. Place cookies on a parchment lined cookie sheet, and refrigerate 30 minutes to prevent spreading. Wash rugelach with egg wash, sprinkle with more sugar and bake for 20-25 minutes or until golden. Cool on a cooling rack.