Adjust oven rack to middle position and preheat to 350°F. Line 2 half sheet pans with parchment or silpat.
In a medium bowl, whisk together the flour, baking soda, cinnamon, and salt. In a large bowl, vigoriously whisk the melted butter and sugars until the mixture takes on a lighter consistency and slightly pale color. Add the egg and vanilla extract until mix until combined. Using a rubber spatula, fold in the flour mixture followed by the rolled oats, dried cherries, coconut chips, and walnuts. Cover the bowl and chill, at least 1 hour.
Divide into 14 portions, about 50 g each, and arrange on prepared sheet pans. Bake until pale gold around the edges, about 15 minutes. Cool directly on sheet pans until firm, about 10 minutes.