panetteria is bakery pasticceria is a cake shop In a panetteria you can also find sweets and cakes usually, but a pasticceria is a more specific shop for cakes, pastries, chocolate...

pasticceria = pastry shop / cake shop ( where they make and sell cakes, sweets and biscuits but in Italy it is common to find the cafe-pastry shop) panetteria = bakery ( sale of bread and sometimes even sweet biscuits and pizza)

/panetteria/ is obviously from /pane/. /pasticceria/ is from /pasticcio/, and from /pasticcino/, where /pasticcio/ has two meanings (one meaning is : complex food preparation), and /pasticcino/ is just the kind of sweet /pasticcio/ (Eng.: pastry). Don't confuse with /pasticcione/,it has a completely different meaning!