In a medium bowl hand whisk together flour, cocoa powder, ground ginger, and baking soda. Set aside.
In bowl of stand mixer with paddle attachment, beat together softened butter and brown sugar until fluffy.
Add egg yolk, sunflower butter, maple syrup, and vanilla. Mix on medium speed until smooth and creamy.
While mixing on medium low speed, spoon in flour mixture slowly until thickens into cookie dough. Scrape bottom and sides of bowl with spatula as needed.
Cover bowl with plastic wrap and refrigerate for 30-40 minutes.
Meanwhile prepare two cookie sheets with parchment paper or silpat mats. Preheat oven to 325 F (160 C).
Remove cookie dough from fridge. Scoop out a 2 Tbsp amount of dough and roll into a ball. Place on cookies sheet and repeat with remaining dough. Space dough balls 2 inches apart. This would be 6 cookies per sheet.
Take a single tablespoon measuring spoon and press down in the center of each cookie. This will give you a small divot once baked to help hold the caramel sauce. (cookies will spread on their own without this step.)
Place cookies on middle to lowest rack. Bake for 12-14 minutes until lightly darker on the edges. They will look slightly soft but firm as they cool. The bottom will have a nice firm texture. Remember these are soft chewy cookies, don't over bake them.
Once cookies are cool, add a dollop of caramel sauce to the the center and sprinkle with flaky sea salt. (optional)