Don’t preheat the oven yet because the dough requires chilling and freezing.
Mix flour, baking powder and baking soda together and set aside.
Mix eggs, vanilla and salt in a second bowl; set aside.In a mixing bowl, mix both sugars, melted butter and oil.
Add egg mixture and stir just until mixed, then add flour mixture and stir just until mixed. Stir in chocolate and nuts. Scoop the batter into sections of equal size and put them on a parchment lined plate or cookie sheet.
Put them in the freezer for about an hour or until frozen.Preheat oven to 400 degrees. Working in half batches, place 8 frozen dough balls onto a parchment-lined cookie sheet.
Bake on center rack until set, but not brown, 8 to 10 minutes (if you’ve made the dough sections smaller, bake 5 minutes). Reduce oven temperature to 350 degrees. Continue to bake until cookies are golden-brown around the edges and lightly brown on the top, about 8 to10 minutes longer.