Accidental house tapping
There is an option to turn it off. Open up the build menu and tap the "i" in the top right corner, then check the box for confirm donut spending.
Forum Discussion
I think the OP wants the ability to use donuts as speed ups to be removed from the game as a whole. That will never happen, because as long as there are people willing to buy donuts for that purpose, you'll be able to speed up.
