In what was called 'a great day' by the nation's educators, a cash-strapped Defense Department held a bake sale in the Pentagon courtyard yesterday to raise money for a new B-1 Bomber. 'Gen. William A. Bratton told me we were about $220 million short for the brand-new bomber we all had our hearts set on, so I decided we should hold a big bake sale,' said Col. Charles T. Lathrop, who, according to unnamed Pentagon insiders, made more than two dozen lemon cupcakes for the event. 'So far, we've raised over 65 dollars.' The department plans to follow up the sale with a car wash. 