@Quadgirl,
Your body will not remember (or care) about a single day of crappy BG.
But YOU will remember the triumph of the day. And it will empower you to do more stuff on another day.
Don’t over-think it, don’t compromise, don’t give in, don’t chicken out. Just do it. Take a bunch of insulin and eat the cake.
I agree, I posted the long thing above your post because it is alway good to have a better understanding of how macronutrients raise or delays in BG rises.
The other day, I did a bicycle ride an hour after eating dinner which I bolused for and a serving of cheesecake which I did not. This ride was just 7 miles which is nothing much. At 4 miles my BG dropped to 65mg/dl and I ate 2 glucose tablets. A mile and half later BG dropped to 55 and I was having hypo symptoms and loss of legs (if you know what I mean). I ate a package of peanut butter crackers worth about 21g chewing slowly and drinking water. I soon felt better and got back on the bike to get home. Whoo Hooo! Down hill.
The carb combination began a roller coaster of BG up and down. No more hypos but definitely out of my self-imposed high range of 145mg/dl with a peak at 167mg/dl.
For me, it’s the opposite. Higher fat slows the BG rise, so it makes it easier for me to avoid a big spike. It’s possible that I’m using more insulin because of the fat, but my BG doesn’t spike as hard. I guess this is another of those YDMV things, where each of us gets to find out what works best in our own body.
I suspect that to be true for those I would call pure type 1s without the genetic propensity to cellular insulin resistance.
Even among us type 2s how insulin resistant we are varies between individuals. Add stress to the mix just really complicates things.
There are generalizations about diet and insulin which will have elements of truth, but are like all generalizations false.
@Eric Thank-you, Eric. I am grateful always for your succinct way of looking at things and this is my natural impulse here! I have overthink and made myself depressed about even having to spend time on this. I definitely will not chicken out and will do the exact cake as planned and will not die as a result. I am now going to have positive anticipatory joy waiting for my birthday and I will have my cake and eat it, too! And one way or the other, I will learn something. Thanks for the reminder to stop over-thinking. And the breath of fresh air. I sure love to hear from everyone and then go with what I know is right. Yay!
@bkh @CarlosLuis Thanks for the citations of macro nutrients, CarlosLuis. I do appreciate it. And bkh, thanks for opening my eyes more to our differences as individuals. I sort of think I am an anomaly sometimes, but don’t know for sure yet. I am thinking and feeling I may be like you in this regard. Plus, I will eat cake in the daytime and it will be a good exercise morning as well. And I enjoy walking, so I may stroll, or even sprint some if I feel it, after I eat cake. I may do nothing, but will be open to whatever. I am looking forward to it! I have never even square bolused (just made what I called corrections). I will employ a strategy and go with the flow. Thanks for sharing!
@needlesandmath Gosh! Thanks for the visual as well. That is mighty impressive! I think like Eric said, I may just come through this with a new way to look at things and continue to do the necessary experimentation for the things I want to eat outside of my routine, cautious way of eating (really can count them on one hand) and come out the other side with a plan like you have for your pizza meal. I love knowing that this can be done. Thank-you, thank-you, thank-you! I sure appreciate the specifics you gave.
@Eric Quick question - when you say pre-bolus, did you mean the entire guesstimate of carbs for the cake, or a portion? I am making my plan! I have a few weeks and I am doing this, come hell or high glucose, or the low glucose and more cake, “I’ll take another, sir!” Don’t remember which movie that is from, Caddyshack, Animal house. . .? So excited!
@Quadgirl, as you have seen here, there are a million different ways to do it. You can pre-bolus some, and then take the rest later. You can do an extended bolus if you are using a pump. You can calculate your current BG, add correction factors, and then factor in different food absorption rates. On and on it goes.
But really, no matter how many formulas you have, it comes down to experience. The more times you do it, the easier it becomes. You get better at it.
As a general rule, for things that are very sugary and fast-acting (not slower carbs), the most important thing is to have enough insulin ahead of time.
Why? Because sugar will come in a lot faster than insulin!
So give your insulin a “head start”. Because the cake will be faster than the insulin!
Try to be trending down when you start eating.
How much should you pre-bolus or what percentage should you pre-bolus? It depends on how safe you feel if you are low. For me, it does not really matter how low I get. I can still eat! As long as I have not lost consciousness, I will eat the cake.
It’s pretty much a survival instinct for me. So I just blast a bunch of insulin and then eat the cake. And I eat more later if I still need more sugar.
Check out this post, talking about survival mode. As long as I am not asleep, my body knows to eat. Not sure if you are that way, but for me, I don’t have a problem just taking all of the insulin up front!
BTW, this was not a planned thing. This was simply my instinct responding to a low. 
Wow! Good to know!
@Eric Thanks! I am like you - and the night I feared I would die, I surely ate, then ended up walking fast at 2am, stopping at what I thought was a conservative 150 (having, for the first time ever, gone from straight down arrow to double straight-up arrows, so dressed and headed out. To, of course, go low again. I think cake will be a much better low treatment than glucose tablets! I plan to try to enjoy and see this as a learning experiment to be conducted over and over until I have what works for me. And, then try the same with the few meals I would love to have on occasion and have a well-rounded life and eventually intuit what to do in various scenarios. I like your way of not measuring and calculating! I have, this year, even used “tare” on my kitchen scale for a dern napkin! And diabetes does not respect measuring perfectly as every day is a new day! I am ready to move beyond the victim stage. And, btw, I am currently back to MDI having had the t-slim get pulled loose and painful, and then fully pulled out while trying to sleep and having to go through the long, to me, process of being bleary-eyed and trying to put in a new cartridge middle of the night and not get air bubbles. Then, just got tired of it and took the new one off the next day because it also was not significantly better than me doing shots. My endo just ordered my OP5 refills when I informed them, but I may try to wait until iphone integration. I hate carrying stuff. And I am in the phase of loving shots right now and letting my skin heal. I will feel mdi’s limitations soon enough, though, so OP5 will return and this time I may begin to be brave and run it on manual since it was a slow learner before. Tandem’s algorithm worked better for my exercise - I think due to it looking only 30 minutes, versus an hour, into the future just worked better for me - more responsive on control IQ than OP5 which would let me sit high forever sometimes. Anyway, I will learn to eat cake on shots and then it will be a piece of cake on the pump! Sorry for the pun. But not really!
This. 100%.
It’s easy. Eat the cake. Bolus and watch BGs. Enjoy the day.
Wait, wait, wait. If the infusion set pulled out, why would you have to change the cartridge? Just disconnect the tube end from the old pulled-out set, put in a new set, (throw away it’s tube), and reconnect the old tube to the new set. And fill cannula.
@bkh Yes, sorry for the omission - that cartridge was due to be changed the next morning anyway. Forgot to mention that. And, I think I was tired of having the device to be aware of every time I rolled over at night (alot - don’t like sleeping on one side too much) which made my sleep not too good. T-slim algorithm married to OP5 tubeless with a cannula that stayed in me better would be my ideal machine! Anyway, thanks for reminder about that particular feature of t-slim that bests an OP5 that come out. Take care.
You know, if you want to eat Key Lime I think you should. Check your blood, try and calculate the carbs and take some fast insulin and dig in! We can’t always be so strict with ourselves. Check your blood again! Totally understand wanting to feel free about food choices. Personally find after a few bites my craving is satiated and I just let it go. Just have what you want and take some insulin. It’ll be okay. 