Heat oven to 350 degrees.
Mix flour, baking powder, baking soda, cinnamon and salt in a bowl. Set aside.
In a very large bowl, beat butter with an electric mixer on medium speed until smooth and creamy. Gradually beat in sugars and combine thoroughly.
Add eggs one at a time, beating after each. Beat in vanilla.
(Switch to now mixing with a rubber spatula or wooden spoon.)
Stir in flour mixture until just combined.
NOTE: You may reach a point when you're blending in the flour and remaining ingredients that you feel like things will never come together. It will ... just keep stirring. This becomes a very thick, hearty dough by the time that all ingredients are incorporated.
Stir in chocolate chips, oats, coconut and pecans (if using).
For each cookie, drop a heaping, rounded tablespoon onto a baking sheet lined with parchment paper ... spacing 2 - 3 inches apart. (Eight cookies per large baking sheet works best so that the cookies do not touch once baked.)
Bake for 8 - 10 minutes or until edges are lightly browned and cookies are still slightly doughy in the center. (Rotate baking sheet halfway through.) Allow cookies to cool on sheet pan for 2 - 3 minutes on counter, then transfer cookies to a wire rack to cool.