Tony cannot, for the life of him, make a decent slice of toast. It's something that Bruce finds ... rather more amusing than he should.
In part, he thinks, because it's not always Tony's usual 'absent-minded genius' thing. Which is not to say Tony doesn't, say, put some in the toaster and then have a thought, and promptly forget about the thing. That wouldn't be at all bad, because the thing with toasters? Or at least, with Tony's toasters? You can programme them. They pop. You don't have to actually watch them. Which means that the products of Tony's absent-minded professor routine aren't charred carbon, they're stone cold instead, at least by the time he notices them. (And providing he hasn't absently knocked the dial from 'lightly done' to 'carbonised').
If you wanted Tony to burn the toast ... Well. For that you needed a Tony who'd already tried the toaster route, and wanted to reheat the toast, or a Tony who had decided that toasters were for lesser mortals anyway. A Tony who'd spent his life getting what he wanted by the shortest possible route, who wanted something hot, and at the same, a Tony who'd spent most of his waking life living in a workshop and working with metals, and who's best friend was, consequently, an acetylene torch.
There are times Bruce wonders if Tony realises there's a reason Dummy is always so trigger-happy with the fire-extinguisher. Or that there's a reason Bruce always tries to be present for breakfast, and that is, because it's the funniest time of the day, and there are days Bruce needs that like he needs air, and science, and an exact knowledge of where all the fire blankets are chez Stark. Days when the world is closing in on him, and the monster under his skin is riding close, and he just ... wants something small, and simple, and real, like a dripping Tony Stark holding a blackened, sodden lump of ex-toast, and glaring at Dummy for all he's worth.
There are times when Tony Stark is good for the soul, is what he's saying. Often, the same times you need to have a fire-extinguisher handy, but ... Well. As Tony would say, that's all part of his charm.
Bruce isn't ever going to admit it, but ... there are times he kind of agrees.