For almond dough:
Cream together butter and cream cheese; add powdered sugar. Add vanilla and egg; mix well. Mix together salt, baking powder, flour and ground almonds; add gradually to butter mixture. Chill for two hours.
For chocolate dough:
Mix the sugar, cocoa and salt in a small bowl; set aside. Beat the butter with an electric mixer in a large mixing bowl until smooth. Add the cocoa mixture. Continue beating until dough is light and fluffy. Add the egg. Gradually beat in the flour. Chill for 2 hours.
To assemble cookies:
Divide each of the two doughs in half. Roll each half of dough between wax paper into a 9 x 12-inch rectangle. Remove one sheet wax paper from each rectangle. Lay one layer of almond dough on top of one of the chocolate dough and lightly press together. Remove wax paper from the top of dough. Roll up dough tightly beginning with a long side, removing the wax paper on the bottom as you roll. Repeat with remaining two layers of almond and chocolate dough. Chill for at least 2 hours.
Heat oven to 350° F. Cut each roll into 1/8-inch thick slices; place on ungreased baking sheet. Bake 10 to 12 minutes.