Convert date to String

Hey everyone!

I am trying to create a column with just the month and the year of a date, so later on I can group the data as I want.

I am using the following line: 

= Table.AddColumn(Source, "MonthInCalendar", each Date.ToText([Created], "MMM yyyy"))

But it gives me the following error:

Expression.Error: We cannot convert the value #datetime(2019, 3, 11, 13, 35, 30) to type Date.
Details:
Value=11/03/2019 13:35:30
Type=[Type]

It is weird because I have been abe to use this before in similar cases without any errors. Is there something I should change in that line for this particular case?

Thanks in advance!