Preheat Oven: Preheat the oven to 350° and line a very large cookie sheet with parchment paper.
Cream Butter & Sugars: In a large bowl (I use the largest bowl I have!), cream the butter, white sugar, and brown sugar with an electric mixer until well combined.
1 cup butter, 1 ½ cups sugar, 1 ½ cups brown sugar
Add Peanut Butter, Eggs & Vanilla: Add the peanut butter and beat until well mixed, then add the eggs and vanilla and continue to beat until everything is incorporated.
½ cup peanut butter, 3 eggs, 1 tablespoon vanilla
Add Dry Ingredients: Add the flour, baking powder, baking soda, cinnamon, and salt, and continue mixing with the electric mixer until combined.
3 cups flour, 1 tablsepoon baking powder, 2 teaspoons baking soda, 1 tablespoon cinnamon, 1 teaspoon salt
Add Mix-Ins: Using a spatula or large spoon, mix in the oats, chocolate chips, pecans, and coconut until combined.
3 cups old-fashioned oats, 3 cups chocolate chips, 2 cups chopped pecans, 2 cups coconut
Shape Cookies: Using a ¼-cup ice cream scoop, drop the cookie dough onto a large cookie sheet, leaving about 3 inches between cookies. Flatten slightly.
Bake: Bake for 15–18 minutes, or until just set and the edges start to turn light brown.
Cool: Cool on the pan for 3–5 minutes, then move to a wire rack to cool completely before storing.