Create Buy Now Button Anywhere!

I want to put a button on my cart (gif image that says BUY NOW) and when people click it, the item will add to their cart. They won't need to visit the actual product page and ADD TO CART but just click BUY NOW from any page and see the item get added.

Is this possible? I wasn't sure if there was a code to add a product to the cart via any page on the site.

I understand if I have product options, the site defaults to the page to key in details but if I have no options, should the buy now button work?