Using a serrated knife, cut angel food cake into 12 equal slices; set aside.
In a mixing bowl or food processor, combine both cream cheeses, sugar and vanilla. Mix until blended and smooth. Combine cocoa and grated chocolate in a separate bowl; set aside. Pour espresso into a shallow dish.
Dip 4 cake slices into espresso mixture and turn to coat. Place slices crosswise in bottom of an 8-inch loaf pan and press cake down to coat bottom (break up cake if necessary to coat surface).
Gently spread 1/3 cream cheese mixture over cake layer. Sprinkle with 1/3 cocoa mixture. Repeat procedure with remaining cake slices, cream cheese mixture and cocoa mixture to make 3 layers.