I typically find it smells worse when I make the butter as opposed to when I bake it into something. It will still smell a little though when baking, depending on the strength of the butter.
I like to make cannabutter using a crock pot, a stick or two of butter, and a bunch of trim. Add the trim and butter to the crock, then top it off with water. Leave for 10-12 hours on LOW (I usually start it at high for a couple hours and switch it to low after an hour or two), stirring occasionally and adding more water if necessary. When finished, I strain out the plant material using a standard grocery store tea strainer, and put the butter + water mixture into a large dish/bowl and put in the fridge for a few hours. The butter will form a visible layer on top of the water which is easily removed once hardened. I wrap the finished product in foil and toss it in the freezer until I need it.
The beauty of this method is it traps the nasty unwanted plant material in the water, which you then discard once you've removed the butter.
One stick of butter can hold a ridiculous amount of THC (in the range of ounces), so it is up to you how strong to make it.
I whole-heartedly disagree with the comments of Harrekin above that making butter doesn't smell too strong. It stinks up EVERYTHING when making it, far less so when baking with it.