I'm very sure there is no such things as custom crafting recipe in SBD. To make it clear I'll tell you some information:
Ursine Hide, Lucky Coin, Kraken Scale, Dragons Eye, etc.. are Rare Boss Drops which is needed to unlock certain levels in /level
Glacial Shards, Ribs, Villager Cash, Baby Sharks, etc.. are Common Boss Drops which can only be sold in /shop > Prestiged Loot
Talking about Recipes, just in case you don't know, most Custom Crops need their own recipe in order to unlock that specified Custom Crops. To get their recipes, you only need to kill minions on bossworld with related custom crops for a small chance to drop the recipe.