Reddit mentions of Quest Nutrition Quest Protein Powder, Unflavored, 25.6 Ounce (Pack of 1)

Carbquik and Quest Multi-Purpose Powder both make keto baking amazing. Carbquik makes better biscuits, Quest makes better bread, have yet to try cookies/cakes/muffins.

One of the best bread alternatives I have used on a low carb diet is actually made from Quest Multi-purpose powder. I have made "rolls" with this and then eat it like a sandwich or have made breakfast sandwiches with it or even slapped a hamburger in it. You will definitely need to add some spices to it so that it has a little flavor because otherwise it is pretty bland. You can Google a ton of recipes.

Another option would be to buy those huge butter lettuce leaves and do a sandwich or burger between a couple of them. Jimmy John's actually offers something similar to this called an "unwich".

For pasta- check out zoodles or spaghetti squash. I prefer the spag squash and I often make chicken meatballs in marinara over spag squash and it is delish. I usually have a salad with it to help fill me up because a huge salad with a ton of lettuce & greens are volumous and filling.

For rice- cauliflower or broccoli rice are decent substitutes. But I will be honest, I am a huge rice lover and these don't really do it for me. I would almost rather go without. I make my own version of Chipolte bowls and what I typically do is a combination of real brown rice and caulirice. So if I want a cup, I will do 1/3 brown rice and 2/3 caulirice. Then I throw on a little bit of black beans, chicken, salsa & guac. AND I put the whole thing over a huge bowl of lettuce.

Have you possibly considered Quest Multipurpose Mix? I haven't bought it personally (yet) but I imagine they made it for the exact reason you're looking for- no flavoring but used as a baking base. Amazon Link