Preheat the oven to 350¡ãF and line a cookie sheet with parchment paper.
Use a mixer to cream the butter and brown sugar together - about 1 minute. Add the egg and vanilla and mix to combine.
In another bowl, whisk together the flour, baking powder, baking soda, and salt. Ad the dry mixture to the butter mixture and mix on low to combine. Add the oats and mix to combine. Add the cherries, pecans, pistachios, and chocolate chips. Mix to combine.
Use a 1/4 cup dry measuring cup to portion the dough out into 16 to 18 equal portions. Roll the dough into a ball (about 2-inches) and place it on the baking sheet. Space the dough balls about 3 inches part and press each ball to about 1 inch thick. Sprinkle with a generous pinch of flake salt.
Bake for 15 to 18 minutes or until the edges are brown but the center of each cookie still is shiny/wet. Cool on the baking sheet for 5 minutes before sliding the parchment, with the cookies on it, to a wire rack to cool completely. Work in batches to bake all the cookies. Store in airtight container.
Notes
For that gourmet look, place an additional 1/2 cup each of the pecans, pistachios, and cherries and in a small bowl. Once the dough balls have been formed, press them into the nut mixture and place back on the baking sheet - ensuring the dough is about 1 inch thick - then bake as directed.?