Mongoose update elements in two collections

I have two Schemas

var recipeSchema = new mongoose.Schema({
    name: String,
    products: [{
        product: Product,
        weight: Number
    }]
})

var productSchema = new mongoose.Schema({
    name: String,
    weight: Number,
    price: Number
})

module.exports.updateProduct = function(req, res){
    var productId = req.params.productId;

    Product
        .findById(productId)
        .exec(function(err, product){
            if(err){
                console.log("Error finding product");
                res
                    .status(500)
                    .json(err);
            } else if (!product){
                res
                    .status(404)
                    .json({
                        "message": "Product ID not found"
                    });
            } else {
                product.name = req.body.name;
                product.weight = parseInt(req.body.weight);
                product.price = parseFloat(req.body.price).toFixed(2);

                product.save(function(err, updatedProduct){
                    if(err){
                        res
                            .status(500)
                            .json(err);
                    } else {
                        res
                            .status(204)
                            .json();
                    }
                })
            }
        })
}

I want to update Product in two documents at once. I wrote piece of code which update Product in products collection. But I don't know how to update Recipe's Product.

For example: Recipe:

{
    "_id" : ObjectId("596d281a4b49abec4abd3d48"),
    "name" : "Cake",
    "products" : [ 
        {
            "product" : {
                "_id" : ObjectId("596d27a24b49abec4abd3d3c"),
                "name" : "sugar",
                "price" : 12.34
            },
            "weight" : 100
        }
    ]
}

Product

{
    "_id" : ObjectId("596d27a24b49abec4abd3d3c"),
    "name" : "sugar",
    "price" : 12.34
}

I want to update Product and Recipe's product at once. Is it possible?