In a medium bowl, mix sweet potato, coconut, honey, egg whites, salt, lemon zest, and ground almonds. Mix until a dough forms, it will be soft and sticky. Cover and place in fridge for at least 1 hour or up to 2 days.

Preheat oven to 325°F. Line two cookie sheets with parchment. Position racks in the upper and lower thirds of the oven. Scoop level tablespoons of the soft dough and roll into balls about 1 1/4 inches. Place 1 1/2 inches apart on prepared cookie sheets.

Bake for 18 to 24 minutes, until the cookies are slightly crusty on the surface (though still very tender and moist inside) and deep golden brown on the bottom. Rotate the pans from top to bottom and from front to back halfway through the baking time to ensure even baking.

Cool the cookies completely before storing. May be kept in an airtight container for up to 4 or 5 days.