An excellent post which you should read and reread for the non DARVO answers that will shut him down.
Also @Gloriously advising you physically remove yourself from the conversation.....let him argue with an empty chair🤚.
OP, you keep writing that your husband doesn't and can't understand your position.
STOP THINKING THIS.
He understands completely.
But it doesn't suit him to understand so he lies that he doesn't get it.
The ugliness of your MIL's response to the cakes, and your husband obtusely repeating it, tells you EXACTLY how aligned they are.
YOU are for USING and ABUSING.
Your husband is absolutely RUTHLESS.
YOU don't know him at all.
HE doesn't want to be near caring duties, so his sole focus and energies are to bully and grind you down.
This will get a lot worse.
I'm nearly 60 and have seen variations of this played out in my large wide circle of friends and friends of friends over the decades.
There is NO ONE as focused as a man who doesn't want to be inconvenienced.
Remember he is set to inherit.
HE wants you protecting his inheritance.
Keep saying "let them pay for help".
I am so sorry but the truth is, he absolutely doesn't love you, not real true long lasting love.
No one who loves you, bullys you to do their bidding.
You need to organise an alternative Christmas for yourself.
Have it quietly sorted without his knowledge.
When he ramps up the bullying before Christmas, pack up and leave and tell him to head off to his parents as you will spend it with others.
Your marriage will likely be over as this continues.
He will bully and bully until you find that you have detached from him.
Please be prepared for how ugly they will become towards you as he ramps up his abuse.
Do not get pregnant.
He may well try to get you pregnant to trap you.
I know that sounds awful, but such is his single-mindedness, nothing would surprise me.
Tell family and friends what is going on and I really think you should return to full time work.
Do not be vulnerable with this man.
He is not to be trusted.
Keep posting.
By posting you will have a clear record to reread of him ramping up his bullying and abuse of you.