Line two rimmed baking sheets with parchment or silicone mat.
In a small bowl, measure and add in the flour, baking soda and salt. Whisk to combine and set off to the side.
In the bowl of your stand mixer, fitted with the paddle attachment, add the softened butter and mix on low until creamy and light in color.
Scrape down the sides of the bowl before adding in both of the sugars. Mix until incorporated.
Add one egg at a time, mixing well after each one. Add the vanilla withthe last egg.
Again, scrape down the sides and bottom of the bowl before adding in the flour mixture, adding a little of it at a time until incorporated.
Add in the oats and mix before adding in the chunks of chocolate. Use a spatula to fold in the sunflower seeds in by hand.
Use a small 2-tablespoon scoop to measure out the cookie dough onto the prepared pans. Bake at 350° on the middle rack in your oven for 10 minutes, rotating the pan halfway through baking.
Allow the cookies to cool on the pan for 1 to 2 minutes before transferring them to a wire cooling rack. Repeat with the remaining dough.