Your simpler, quicker, easier visa 
Custody of an EEA Child
I am a non-EEA National parent of a EEA child in full time education in UK
You can apply for a UK Residence Card if you are a non EEA national and have custody of of an EEA national child, who is in full time education in UK. .You need to show that the EEA Child is in UK after arriving with a Parent who was exercising treaty Rights.
You need to show that you will be able to maintain yourself without becoming a burden in the public resources, or that the child’s other EEA national parent is still exercising treaty rights in the UK.