ThisRocks/src/main/resources/data/rocks/recipe/granite_from_splitter.json

{
    "type": "minecraft:crafting_shapeless",
    "ingredients": [
        {
            "item": "rocks:granite_splitter"
        },
        {
            "item": "rocks:granite_splitter"
        },
        {
            "item": "rocks:granite_splitter"
        },
        {
            "item": "rocks:granite_splitter"
        }
    ],
    "result": {
        "id": "minecraft:granite",
        "count": 1
    }
}