Preheat oven to 350F degrees. Line baking sheets with parchment paper (do not use nonstick cooking spray).
In a large bowl, whisk together 4 cups flour, 2 teaspoons baking powder, 2 teaspoons baking soda and 1 teaspoon salt, if using. Set aside.
Place 2 sticks butter, 1 cup plus 2 Tablespoons shortening, and 2 cups brown sugar, 2 cups granulated sugar in the bowl of a stand mixer fitted with the paddle attachment and beat on medium speed until creamy. Reduce the speed to low and add 4 eggs, one at a time. Do not overmix once the eggs are added. Add 3 teaspoons vanilla. Add the flour mixture a little at a time, and blend until smooth. Remove the bowl from the stand.
Mix by hand from this point forward.
Use a spatula or large spoon to fold in 2 cups oats, 2 cups cornflakes, 1 ½ cups chocolate chips, ½ cup macadamias, ½ cup pecans and ½ cup dried cranberries.
Use a large cookie scoop or using a kitchen scale, measure 2.5 oz. balls, 3 Tablespoons. Place round balls on the baking sheet, placing cookies about 2 inches apart.
Bake for 12-13 minutes, until cookies are barely golden on the edges, but still look a little underdone. Remove from the oven and cool for 5 minutes. Transfer to a wire rack to let cool completely.
Dough freezes well and cookies do too.