Step 1In the bowl of a stand mixer, or in a large bowl using an electric mixer, beat the butter and cream cheese until combined. Add the sugar and continue to beat until light and fluffy, 3 to 4 minutes. Beat in the salt, then slowly beat in the flour until thoroughly combined to form the dough.
Step 2Divide the dough into 8 equal pieces. Flatten the pieces into disks and wrap in plastic wrap. Refrigerate until well-chilled, at least 1 hour.
Step 1Heat oven to 350 degrees. In a medium bowl, stir together the sugar, chopped cherries, walnuts, butter, cinnamon and allspice to make the filling.
Step 2Unwrap one of the dough disks onto a lightly floured surface. Roll the dough into an 8-inch square. Spread one-eighth of the filling (about one-fourth cup) onto the center of the dough with the back of a spoon, leaving about a one-half-inch border on the top and bottom of the dough.
Step 3Starting at the top, carefully roll the square into a tight roll like a jelly roll. Using a sharp knife, slice the roll crosswise into three-fourths-inch pieces, discarding the ends.
Step 4Place the cookies on an ungreased cookie sheet and repeat with the remaining dough disks. Brush each cookie with beaten egg, then sprinkle with the sanding sugar.
Step 5Bake until rugelach are golden brown, about 20 minutes.