VanillaPlus/src/main/resources/data/vplus/recipes/copper_chestplate.json

{
  "type": "minecraft:crafting_shaped",
  "pattern": [
    "# #",
    "###",
    "###"
  ],
  "key": {
    "#": {
      "item": "minecraft:copper_ingot"
    }
  },
  "result": {
    "item": "vplus:copper_chestplate",
    "count": 1
  }
}