Heads up, pancake purists: It's worth the pilgrimage to Rio Ranch [9999 Westheimer, Westchase Hilton, (713)952-5000] for a short stack of tender buttermilk pancakes, gems of the Ranch Hand breakfast ($11.95 buffet or $4.95 $egrave; la carte). So scrumptious, these made-to-order babies don't need to boast a Texas-size girth to engage your attention. Redolent of fresh buttermilk, they are demure but pillowy-plump and spongy, flavored with a hint of sugar and gently griddled until faintly golden outside, moist inside. Pile on the kaleidoscopic array of fresh fruit and warm maple syrup for the ultimate in breakfast feel-good food. Rio Ranch creator, celeb-chef Robert Del Grande, painstakingly tested and retested pancake recipes to arrive at this flawless version. Del Grande, who holds a Ph.D. in biochemistry, won't exactly reveal his secret formula. But he offers this hint: The magic lies somewhere in the precise balance of fresh ingredients.