Follow SS38 until you reach Laatsch / Laces. A little west of the village the road into Martelltal turns off to the left. Drive on through to the end and start your ascent from Enzianhütte / Rifugio Genziano.
Altitude difference: 1300m
Trailhead: Enzianhütte / Rifugio Genziano
Due to the difference in elevation this route is a rather tough hike along Madritschtal / VAl Madriccio. The valley has almost no vegetaition and thus - as you reach the neccessary altitudes - offers great views along the Cima Venezia - Cevedale ridge. Once you get into Passo Madriccio the breathtaking view of the Trinity Gran Zebru - Monte Zebru - Ortler/Ortles awaits you.
Start out from Enzianhütte / Rifugio Genziano at the end of Martelltal. Head for Zufallshütte /Rifugio N. Corsi where the ascent trail along Madritschtal (signed 151) turns right. In fact there are a couple of other trails that pass the rifugio by but I think this is the easiest to find.
At first the trail climbs into the high valley by winding along the cascades of Madritschbach / R. Madriccio. It soon gets to an intesection where a trail to Plattenspitze (33, later 20B) turns right just after you have crossed the creek. Remain on the right hand (northern) side of the crrek and go straight on to Passo Madriccio, which you can see from afar. In the Passo turn right onto the southern ridge of Hintere Schöntaufspitze and scramble to its top.
Hiking gear and obviously warm clothes. Don't get fooled by the weather in Martelltal / Val Martello. This valley is very well protected from any winds. So is Madritschtal / Val Madriccio. But once you near the pass you will be blown away.