In a mixing bowl, whisk together flour, baking powder, baking soda, and salt. Set aside.
Line baking sheets with silicone mats or parchment paper, and preheat oven to 350 degrees F.
In bowl of stand mixer, combine butter and sugars. Beat 2-3 minutes on medium speed, occasionally scraping sides of bowl. Add eggs and vanilla, and beat on high speed for another 2 minutes, scraping bowl. Add dry ingredients, and mix on low speed, just until incorporated. Add chocolate chips, oats, coconut, and pecans, and fold all together.
For Large Size (4-5 inch) Cowboy Cookies: Drop ¼ cup scoops of dough on prepared baking sheets. Leave at least 3 inches between cookies. Bake at 350 degrees for 15-17 minutes.
For Regular Size (2-3 inch) Cowboy Cookies: Drop 1-inch balls of dough on prepared baking sheets. Bake at 350 degrees for 9-10 minutes.
Allow cookies to cool on baking sheet for 3 minutes, and then transfer to wire racks to finish cooling.
Notes
Makes 24 (4 ½ inch) cookies or 48 (2 ½ inch) cookies