Sunflower kernel is a popular snack and a versatile food ingredient. Sunflower kernels add a unique mild taste and a crunch to baked goods. They can be substituted for any nut in a formulation - often at a price advantage. In fact, their small size and texture make sunflower kernels especially well-suited for additional to baked goods. Products containing sunflower kernels are likely to be thought of as healthy products with desirable eating characteristics. Sunflower kernels are, thus, quite well-suited for addition to a variety of bakery products.

Seeds, kernel, what is the difference?
The answer, there isn't a difference. Here is how the NSA refers to sunflower seeds/kernel:

• In-shell means the seed is left intact with the "meat" of the seed still in the shell. It is normally roasted and seasoned. It is eaten as a snack by cracking the shell with one's teeth, discarding the hull and eating the delicious morsel within. 'Chew and spit' is a great American pastime, especially at baseball games and other outdoor events. 
• Kernel means the processor has mechanically removed the hull. The resulting kernel is now in a convenient form to be sold raw or roasted for snacking or as an ingredient.

They’re rich in healthy fats, beneficial plant compounds and several vitamins and minerals. These nutrients may play a role in reducing your risk of common health problems, including heart disease and type 2 diabetes.