Soften Group 1 but do not melt and place in a mixing bowl. Sieve Group 2 and add to the above. Blend on second speed until a fine crumbly mixture forms. Add one third of Group 3 as desired and mix on second speed for 1 minute. Scrape down and add the remaining two thirds of Group 3 over a period of 3 minutes on slow speed. Scrape down thoroughly and mix on second speed for 6 minutes. Oven temperature 171¡C (340¡F).
The metric recipe is of similar size to the avoirdupois recipe but is not an exact conversion.