01 - Preheat the oven to 350°F. Line a 12-cup muffin tin with paper liners or lightly grease with cooking spray.
02 - In a large mixing bowl, combine the oats, almond flour, cocoa powder, sea salt, and baking powder. Mix well to ensure even distribution.
03 - In a separate medium bowl, whisk together the melted coconut oil, maple syrup, brown sugar, eggs, and vanilla extract until completely smooth and emulsified.
04 - Pour the wet mixture into the dry ingredients. Using a spatula, fold gently until just combined. Do not overmix.
05 - Fold in the dark chocolate chips and chopped walnuts or pecans if using, distributing evenly throughout the batter.
06 - Divide the batter evenly among the prepared muffin cups, filling each about three-quarters full.
07 - Bake for 18 to 20 minutes, or until centers are set and a toothpick inserted comes out mostly clean with a few moist chocolate streaks.
08 - Let the cups cool in the pan for 10 minutes, then carefully transfer to a wire rack to cool completely before serving.