TypeScript typing error in Node with MongoDB: OptionalId<Document>[]

I'm successfully connecting and writing to my MongoDB collection but there is a type error I can't figure out. Code and error below:

interface Movie {
  id: number;
  title: string;
  createdAt?: Date;
  ...
}

...

const getCacheConn = async (): Promise<Collection<Document>> => {
  const client = await MongoClient.connect(
    `mongodb+srv://username:password@cluster.1234abcde.mongodb.net/${mydb}?retryWrites=true&w=majority`
  );

  const dbConn = client.db(mydb);

  return dbConn.collection(mycache);
};

const cacheMovies = async (movies: Movie[]) => {
  ...
  const cacheConn = await getCacheConn();
  cacheConn.insertMany(movies); // IDE highlights "movies" here and shows error.
};

The error:

Argument of type 'Movie[]' is not assignable to parameter of type 'OptionalId<Document>[]'.
  Type 'Movie' is not assignable to type 'OptionalId<Document>'.
    Type 'Movie' is missing the following properties from type 'Pick<Document, keyof Document>': close, normalize, URL, alinkColor, and 246 more.

Am I missing something? Is Promise<Collection<Document>> perhaps the wrong type for a collection? I searched around but couldn't find info on this error.

try this:

interface Movie {
  id: number;
  title: string;
  createdAt?: Date;
  ...
}

...

const connectDB = async () => {
  const client = await MongoClient.connect(
    `mongodb+srv://username:password@cluster.1234abcde.mongodb.net/${mydb}?retryWrites=true&w=majority`
  );

return client.db()
};

const cacheMovies = async (movies: Movie[]) => {
  ...
  const db = await connectDB();
  db.collection(mycache).insertMany(movies)
};