What's a good substitute for butter when baking healthy cookies

Butter is healthful. Other products are not.

I c people r inquiring about fat substitution in recipies. & THE ANSWERS r not helpful...Butter IS unhealthy BUT ASIDE FROM THAT..SOME people cant have butter....&/or fats of this degree....Galbladder , pancreatitis, biliary disease.. kidney-liver& heart disease..dairy alergy. Diabetic situations etc. .etc.....SO pushing & pushing Butter use isnt very helpful to people lookn for alternatives when u dont know the situation of the inquirer....

canola oil has worked for me in the past if you take into consideration the extra liquid

I tend to use coconut oil, I'd prefer butter, but don't eat dairy.
I figure a treat is a treat, so it should have a great flavor and the right texture because a few really good cookies are much more satisfying than a slew of good for you cookies(my grandma makes cookies with fruit purees instead of fat and a quarter of the sugar. We call them sinkers. They're not bad, they're just more like a horse treat than a human one.).

I am not afraid of using butter instead of margarine - especially when you consider it is a little amount when spread out over a number of cookies. Check out the chemical formula for various margarines and not the hydrocarbon chains and transfat chains and you will reconsider using butter.

I make oatmeal cookies using half canola oil and half applesause. The main difference is that you get a cakey higher cookie rather than a flat one. If you don't mind that, it works great. Part of the function of butter vs. oil in baking is that there is liquid in the butter that " boils" off creating steam.

I wouldn't substitute applesauce for butter. Also butter isn't unhealthy -- you need fat in your diet -- if eaten in moderation.