Prepare Baking Station : Position oven racks in the upper and lower thirds and preheat the oven to 375°F (190°C). Line your baking sheets with parchment paper for easy cleanup.
Whisk Dry Staples : In a medium mixing bowl, thoroughly whisk together the white whole-wheat flour, ground cinnamon, low-sodium baking powder, and sea salt.
Cream Butter and Sugars :In the bowl of a stand mixer, beat the softened butter with the brown and coconut sugars on medium-high speed for 2-3 minutes, until light and fluffy.
Incorporate Eggs and Vanilla : Reduce mixer speed to low. Add the eggs one at a time, followed by the vanilla, mixing until just combined.
Combine Wet and Dry :With the mixer on its lowest setting, gradually add the flour mixture until just combined. Do not overmix.
Fold in Final Ingredients : Remove the bowl from the mixer. Using a spatula, gently fold in the rolled oats and dark chocolate chunks.
Portion the Dough : Using a 1 ½-tablespoon cookie scoop, drop rounded portions of dough about 2 inches apart onto the prepared baking sheets.
Bake to Perfection : Bake for 9 to 11 minutes, rotating the sheets halfway through, until the edges are firm and golden-brown. Cool on the pan for 3 minutes before transferring to a wire rack.