THE people of Macau have waited for this for 450 years, a delighted Macau government official said, as he enthusiastically waved a custard-filled pastry in the air between us, ''and at last we have a real Portuguese cake shop in Macau.'' The arrival of the Bolo de Arroz in the newly cobbled square outside the Leal Senado caused as big a ripple among Macau's bureaucracy and Portuguese media types as any announcement about the latest meeting of the Joint Liaison Group. And rightly so. After all, the arrival of this little cake shop affects their lives on a day-to-day basis. Where better to schedule a morning meeting than a place where you can buy a long glass of galao (cafe au lait Portuguese-style) for $10, or knock back a brain-waking espresso for only $8? A cup of tea is even more of a bargain at $7. And with the cakes priced at between $3 and $15 each, a tasting session does not leave any noticeable dent in most wallets. During my own tasting sessions over several visits, my top vote went to the bola de berlin, a sweet custard-filled doughnut. The bolo de arroz, or rice cake, after which the shop is named, was quite plain, but according to manager Antonio Castanheira it is most popular with the Portuguese customers, followed closely by the cream-filled nata cakes . Palmiers - morsels made of baked flour egg and sugar with a shiny glaze were slower starters, but catching on with many customers, he said. While popular in Portugal, this is the first time they have ever appeared commercially in Macau. All the cakes are made by a pastry chef brought in especially from Lisbon; his bakery is in another part of town - the tiny premises of the Bolo de Arroz do not have the space for making cakes as well as selling them. And he keeps his ovens hot. Mr Castanheira estimated that about 1,000 cakes a day are sold to customers who want to eat them on-the-spot or take them away, as well as several kilograms of tiny biscuits which are sold by weight over the counter. When the shop opened just before Christmas it had six tables. Now it has three plus a long counter, Lisbon-style, for people to stand with their espressos and morning snacks. This welcoming orange-painted room gives the place a busy feel, and a feeling that it is a place for locals and not just tourists who have also begun to call it their own.