Chocolate chips are small, uniformly shaped pieces of chocolate, usually teardrop-shaped, formulated to hold their shape when baked rather than melt completely into the surrounding dough. They were introduced in 1938 after Ruth Wakefield of the Toll House Inn in Massachusetts cut up a bar of Nestle semisweet chocolate for cookie dough; Nestle began selling pre-cut morsels shortly after. Dark, milk, and white chocolate chips are all available, differing mainly in sweetness and cocoa content. They are most often used in cookies, brownies, and muffins, though they also turn up in a few savory dishes, such as chili or mole-style sauces.