Hokulani Bake Shop   When it opened a couple of years back, Tushar and Ana Dubey's Hokulani Bake Shop found an immediate audience and eager word of mouth (when people could talk around the cupcakes they were devouring). They use pure ingredients (butter, vanilla, high-quality chocolate), no hydrogenated oils with their trans fats, no corn syrup or similar sweeteners, no preservatives, none of the nasty trick products (canned whipped cream, anyone?) that make so many baked goods look 100 times better than they taste. The menu includes signature cupcakes in 10 varieties (or request a custom recipe), and decorated sugar cookies in an almost infinite variety of shapes and gift baskets.  Restaurant Row. 587-7098. 9 a.m.- 7 p.m. Mondays-Fridays; 11 a.m.-6 p.m. Saturdays. AX, DS, JCB, MC, VS. Checks accepted. $.