minecraft-kajetans-mod/src/main/resources/data/km/recipes/spikes_copper.json

{
  "type": "minecraft:crafting_shaped",
  "pattern": [
    " # ",
    "###"
  ],
  "key": {
    "#": {
      "item": "km:copper_ingot"
    }
  },
  "result": {
    "item": "km:spikes_copper",
    "count": 3
  }
}