Spanish Henry Miller

Does anyone know of a Spanish essayist that might be thought of as that fine country’s Henry Miller? A Latin American Henry Miller would work too. I’m in Madrid and want to read a little in the native tongue while I’m here…

So far I think I might like Terenci Moix or Francisco Umbral, though I’m also considering reading Ortega y Gasset for the first time, but any and all recommendations would be appreciated. Familiarity with Nietzsche would, of course, be a plus.