The easiest way to climb Pizzo Quadro, known also as Cima de Pian Guarnei, is to start from Starleggia village which is above the Spluga road on its west side. This east ridge route is the one I followed, and it is described here.
Climbing Cime di Val Loga
Cime di Val Loga can be climbed in 4-5 hours directly from Montespluga village as a day tour, or you can stay overnight in Bivacco Val Loga as I did.
Sleeping Above Clouds: Bivacco Val Loga
Bivacco Val Loga (ex-Bivacco Cecchini) is at 2773 m (9098 ft) of elevation, and equipped with beds and all you need for sleeping. You can visit it as a day tour or spend the night there.
Climbing Pizzo Paradisino (Piz Paradisin) from Italian Side
Pizzo Paradisino (Piz Paradisin) is on the border between Italy and Switzerland, and it can be climbed from both sides. The climb from the Italian side is described here.
From Forcola Pass to Pizzo Orsera
If you are at Forcola Pass, you might want to climb Pizzo Orsera, the route starts directly at the pass, and you will need two hours and a half to get to the summit.