I'm sure nothing is going to stop them.

They shouldn't as it could make them very sick. They shouldn't eat sugary foods, or faty foods and they don't eat grains. They should be eating hay, grasses, veggies and fruit. But no dairy, grains, seeds, nuts, or fat.

I don't see why not... how ever if they get sick you know what the illness would be from - LMAO

only if they drive to the local Krispy Kreme to buy them.

my rabbit enjoys eating cookie and brownie pieces he finds on the floor

This is a repost from another question I answered, because I'm too lazy to retype all of this information: I'm an Avian and Exotic Veterinary Technician. Rabbits are smart. It's totally normal for a rabbit to want to eat things that taste good (i.e. carrots, fruits). Fruits contain sugar--they taste good--that is why they like them and will generally choose fruits over vegetables. These items are not beneficial to the health of your rabbit. Rabbits are herbivores and should remain such. Items that contain sugar (fruits, carrots, cookies, etc) can throw off the bacteria in their gut and place them into gastrointestinal stasis (when their gut slows down and stops moving), which is an emergency situation. If your rabbit ever stops eating or producing stool, bring him to a vet immediately for supportive care (pain meds, sub-q fluids, assist feeding). The diet of your rabbit should consist of this and nothing else: 60% Timothy Hay (No Alfalfa Hay; contains sugars; not as tough to grind as Timothy hay and thus does not aid or prevent dental disease) - It is also fine if your rabbit eats 100% Timothy Hay, so long as you notice him eating a good amount and producing stool. He should never be without Timothy hay. This is the main portion of his diet. 30% Dark, fiber-full greens: Kale, collard greens, dandelion greens, mustard greens--these are the best. Do not feed Iceberg! Romaine is not very nutrious either, so I would not feed that as well. Just the foods above first mentioned in a salad once a day. Do not leave in cage for more than one hour. Can sometimes cause diarrhea--if so, reduce the amount of greens offered until resolved, or feed straight Timothy Hay and introduce greens in smaller portions. 10% Timothy-Hay based pellets: About 1/4 cup a day, not to be replaced until the following day. No Alfalfa pellets. No extra items like seeds or dehydrated fruits. The main idea of this diet is to promote good GI health and good dental health. As a treat, maybe twice a week, he can have a BABY carrot. Do not feed whole adult carrots as that is too much sugar. He does not need fruits, raisins or bran. Keep this in mind: Food is not love. Improper diet can cause serious issues for your pet. Oxbow Hay company makes awesome foods--check them out online. Also: www.rabbit.org House Rabbit Society--has generally good information. If you have any other questions, please e-mail me.