I got a bit carried away but maybe something help…?
Well I am a hedonist and food is one of my major joy - and I don’t use ANY willpower when it comes to food, it’s part of my personality, really. If I get tempted, I eat the food.
But as I wrote, I am a hedonist. Not a perfect one but yeah, health is super important for me, even more than joy from food (and the latter is extremely important but still, health is even more so. thankfully they don’t tend to be in conflict but yeah, some training and thinking and recipe making was involved).
So… I know lots of sugar isn’t good for me. There are limits so I STILL can’t/don’t really want to resist fruits (I try to keep them to the minimum though and I had carnivore weeks with obviously zero… I am worse now) but added sugar? I hate added sugar. And sugar isn’t even tasty! Just sweet. So it’s usually very easy to ignore it (though I admit it helps that my high-carber SO with an impressively big sweet tooth dislike added sugar too so we simply don’t have such items at home. well I have a condiment with some in it but 1-2g sugar per month from it is something I can live with), I make my own desserts. Even after very many low-carb days, I tend to have some dessert at every meal. But it’s nice, very nutritious stuff. Usually too fatty though but it’s not like I am able to lose fat on keto anyway.
So. 1. I really dislike sugar 2. I make my own recipes. Making them is a great joy too! It’s fun!
And I have training but it’s not regarding sugar. It was super easy to stop eating added sugar for both my SO and I. Sweet desserts were much better than store-bought sugary ones. They aren’t fatty enough anyway… Or protein rich enough if we consider my macro goals…
But if you really need some sweets… I would do for some very satisfying, rich, fatty stuff. Many people use some dark chocolate. I used my own as sugar is such a stupid thing in it, it does absolutely nothing to me, just damages the joy with excessive sweetness (it’s not true for the darkest ones but I dislike those). I love(d? I barely eat it since my carnivore escapades. maybe a tiny bit here and there but it’s not needed anymore) chocolate for the cocoa part, the fat part. My own chocolate became unsweetened (and very fatty) and it was still good. Works well with my sponge cake muffins though I very rarely ate them sweet
They were my bread, very good for sandwich (and I always disliked sandwiches, turned out I just needed them eggy).
Oh and you may need time. I immediately looked at certain things (like sugary store-bought sweets) like “not food” but needed a much longer time for other items (and some sweets were still tempting now and then, maybe due to their texture so I tried to made new recipes).
And it’s good I never want sweets when I am hungry, that way I have a chance to get fully satiated by some very good keto food without needing more than a creamy coffee as dessert… I do have a dessert stomach but it goes to sleep if I just ate 500g pork and some eggs or something. All of my food related problems can be solved by eating the right kind and amount of food at the right time 
I do understand the cake problem though. A few years into low-carb, I always ate a lot of cake when I was presented with some very tasty homemade stuff… Cake shop? I just drank water, the stuff there was too sugary. Oh yeah IDK how common it is exactly but everyone in my family who stopped eating added sugar ended with a very changed sweetness perception. Many fruits and almost all store-bought sweets are unedibly sweet for me (not like I can’t eat the tastier ones with a ton of black coffee but it’s tough to break the wall of my health-consciousness. I really hate hurting myself). I guess carnivore helped more
Normal food (at least eating it all the time as people do it) is kind of weird to me now. My current diet is way more fitting for the needs of my body. My body is very vocal about its needs and desires, that probably helps me a lot now that I think about it… Lucky.
I have this with colorful vegan food
And tried to do it with fruits, well it’s a partial success especially when it’s fruit season in my garden… They are so beautiful! It doesn’t mean I need to eat them (even if I do it to some extent). One can enjoy food without eating it… (Of course, someone must eat my fruits as I can’t throw out food but I pressure can them, my SO pretty much needs them all year round.)
Good idea. I usually have dry sausage. It’s hard to imagine sugary sweets more enjoyable than that (and it’s useful when I ate enough normal food but still need a tiny extra). I like pickles too. And sauerkraut. So if I stop to think, I surely can find some better alternative (except when I want some texture but with my quick super crunchy recipes, it’s much better now).