Can you substitute butter for crisco in a coffee cake?

Not only can you substitute butter for Crisco® in a coffee cake, one should use a shortening other than one containing hydrogenated, and especially, partially-hydrogenated oil like Crisco does. If you use butter, make sure that you use unsalted butter, else you will have to guess by how much to reduce the amount of salt added.
Other shortening alternatives, all of which are better than Crisco, are [pork] lard, [beef] tallow, and palm kernel oil, which is actually a solid at room temperature. Coconut oil, also solid at temperatures below about 76 deg. F, is another possibility. Many brands of lard, and possibly of tallow, are partially-hydrogenated, so make sure that you avoid those. If lard is not available in your regular grocery store, it is almost certainly available at grocery stores that serve a lot of Hispanic customers.
I can already see the comments about how terrible the substitutes I mentioned are. People will comment that butter, lard and tallow, being animal products, contain cholesterol and that they all contain much too much saturated fats.
First of all, the amount of cholesterol contained in the animal-based fats is negligible compared to what ones liver produces. Consuming animal-based fats, in moderation, will not raise ones cholesterol level; either their total cholesterol or their LDL cholesterol.
Second, with one exception, nothing is worse than consuming partially-hydrogenated oil(s) (so that they becomes solids). The reason is that they contain trans fatty acids, which are known to raise ones LDL (the "bad") cholesterol. Only fatty acids containing at least one double bond can exist in the trans conformation about a double bond. This is because the two carbon atoms double bonded to one another and the four substituents bound to those two carbon atoms (two substituents per carbon atom) all lie in a plane; that is, all six atoms are flat. The overwhelmingly vast majority of double bonds in the trans conformation are more stable than the cis conformation due to greater steric interactions between the substituents when they are next to one another. That is why some of the cis unsaturated fatty acids will isomerize to the trans form if that specific unsaturated fatty acid remains unsaturated during the hydrogenation process. By the way, the cis isomers are the ones virtually all plants and animals make.
Third, saturated fatty acids possess NO inherent unhealthy properties. How can this be? We've all heard since we began paying the least bit of attention to health how terrible and insidious saturated fats are. In addition, chances are your regular Dr. has discussed with you the importance of limiting your intake of saturated fats.
The fact is, very few general practitioners keep up with the medical literature. Anything most of them learn after medical school they learn from sales representatives for drug companies. As a result, when one visits his Dr., almost every Dr.'s mindset is to check you out in order to determine if you "need" a particular drug or not.
For the record, never did I want to be a medical Dr., I was never a pre-med student in college, and I never applied to any medical schools nor did I ever take the MCAT exam. However, at one time I did work as an instructor for the MCAT exam; I was employed by the largest exam preparatory company. The MCAT exam, at least the version that existed in the early '90's, was a joke. I hope it has been made difficult by now.
So, what raises ones cholesterol? The consumption of saturated fats does not raise ones cholesterol. The consumption of trans fatty acids and oxidized unsaturated fatty acids is what raises ones cholesterol. I'm living proof, along with millions of others who have educated themselves from the medical literature and not from advertisements from supplement manufacturers or worse, the horrendous "advice" patients receive from their family quack, that saturated fats do not raise ones cholesterol. I consume approximately 40 to 60 grams of saturated fats every day. My total cholesterol levels, measured in early July 2014 and in March 2014, respectively, were 178 and 182 mg/dL. My respective HDL levels were 34 and 31 mg/dL.
I'm almost finished with my preemptive response: High serum concentrations of LDL cholesterol do not cause "clogged arteries," that is, arterial plaques. This is how it actually works. Only LDL cholesterol and VLDL cholesterol containing a sufficiently high percentage of oxidized cholesterol molecules damage any arteries. These particular LDL and VLDL particles are the only ones that penetrate an arterial wall, thereby setting off a cascade of events that culminates in damage to that part of the artery. The process begins with an intense immune response.
The way to protect oneself is twofold: 1) Consume as little oxidized cholesterol as possible. This includes NEVER eating powered eggs and powered protein(s) derived from animal products such as casein. Eliminate the consumption of ALL processed foods. Eliminate eating meats cooked over an open flame or charred meat. Never eat aged cheeses or cured/preserved meats since the cholesterol therein slowly oxidizes as the product ages for many months or years. I limit my consumption of cheeses to those aged less than two months. Finally, use the freshest cholesterol-containing foods as possible. I strongly suggest eliminating milk yogurt from ones diet and replacing it with yogurt made from soy milk or coconut milk. I would also only use unsalted butter since it's highly likely that salted butter is older and contains some butter that had been removed from shelves because it was expired. 2) Consume A LOT of powerful antioxidants. Few compounds claimed to be antioxidants are powerful enough to prevent the oxidation of cholesterol. The most powerful antioxidant safe to take is one that is naturally present in everyone's body; lipoic acid - usually labeled as "alpha lipoic acid." The other truly powerful antioxidants one should take, in my opinion, are vitamin C, milk thistle extract, and plenty of fresh fruits.
Happy Baking!