Skill Book Cooking Vol 2 has a grammar mistake

The Skill Book “Cooking Vol 2: Let’s Keeping Cooking!” is incorrect grammar. 

The title should read “Cooking Vol 2: Let’s Keep Cooking!” Or “Cooking Vol 2: Let’s Keep On Cooking!”

I’m unsure which was trying to be achieved but regardless, where it stands now, the name is definitely grammatically inaccurate.