Easter was very different in the UK (although like Halloween it is acquiring an American flavour now). We celebrated it seriously, being Catholic, but our celebration was even further from the "chocolates and bunnies and egg hunts" than your family's was.
My Dad
did set up a treasure hunt for us one year - clues for my sister & I to find our one egg, and Dad and I repeated it later for my younger brother, but I think that was coincidental (he would sometimes set up fun & games for no reason whatsoever).
On a usual Easter Sunday we would come downstairs and find our egg at our breakfast plate. (Typical
British Easter eggs - chocolate eggs with a bag of sweets inside & sometimes a mug or an eggcup or a toy in the box too). Very occasionally we would be allowed to open it and eat some of the contents before Mass. But the contents are small beer compared to the egg anyway.
Then Mass, really really early so we would get a seat - Easter was always packed out. Before I was 12 my Grandparents lived in London so they would stay with us, as would Grandad's sister (Fatty Alice). After that they moved to Aylesbury - opposite the church in fact - so we would go to their place afterwards. Possibly another egg, possibly some money or a toy. Then all home to ours for the best part of the day - extra special Sunday roast. It was a really joyful occasion despite not having the same haul as Christmas. I loved Easter.
Then the oldies would fall asleep in front of whatever film was on as the Easter blockbuster, and someone would take us out for a walk.
It was special - a proper Christian celebration. A high day. A Holy day. I do miss it in a way.
Anyway, back to you.
I say, have a proper sit-down chat with your other half re this. I accept that he says you were deprived in a tongue-in-cheek way, but the truth is just because something is the cultural norm it doesn't mean that you should follow it. The children I know veer between anarchy and arch-conservatism. Which ever mode they're in at the time, some variation in the routine is good for them.
If he is not willing to put the work in to keep everything identical to what their mother provides then I think he should accept your family's way of doing things. Even if you do the fancy brunch and they hate it, stick to it and I bet in years to come they include it as family tradition.