Java Edition:Snow Layer (Item)
Snow Layer was added in Alpha v1.0.4 but the item form was not normally obtainable until 13w05a (1.5 snapshot) with the introduction of a crafting recipe for snow layers. The snow layer item form could be obtained before the item's recontinuation though, only obtainable once in Beta 1.6 Test Build 3.
Obtaining
Beta 1.6 Test Build 3 Debug Chests
In Beta 1.6 Test Build 3, any newly generated world would contain up to 11 debug chests with every item in the game. The snow layer item was obtainable in the chests 3rd and 7th from the left in the 20th and 4th slots respectively, in stacks of 64.
Crafting
Since 13w05a (1.5 snapshot) snow layers could be crafted from snow blocks.
the crafting recipe for snow layers
Silk Touch
Ever since 17w48a (1.13 snapshot) snow layers would drop themselves if mined with a shovel enchanted with Silk Touch.