Toast and chop the nuts.
Oven to 350 deg F. Line 2 baking sheets with parchment paper.
Whisk flour, baking powder, baking soda, and salt in a medium bowl.
In a second bowl mix oats, walnuts cherries and chocolate.
Beat butter and sugar, add egg and vanilla. Slowly add flour mixture. Fold in the oats/nuts mixture.
Make 16, about 1/4 cup. Roll into balls (about 2 inch diameter), put 8 balls on each baking sheet. Bake 12 minutes, continue to bake until cookies are medium brown and edges have begun to set but centers are still soft (cookies will appear raw, wet and shiny in cracks), 8-10 minutes longer - Do not overbake.
Cool on sheets for 5 minutes then transfer to wire rack.