Tonka beans are the seeds of the Dipteryx odorata tree, native to South America. They are known for their sweet, vanilla-like aroma, which comes from a compound called coumarin. These beans are often used in perfumes, cosmetics, and culinary applications, adding a unique flavor to desserts and beverages. In cooking, tonka beans are typically grated or infused into dishes, but they should be used sparingly due to their strong flavor. While they are popular in gourmet cuisine, it's important to note that coumarin can be toxic in large amounts, leading to restrictions on their use in some countries.