In a large bowl, whisk together almond flour, coconut flour, cocoa powder, baking soda, baking powder and salt.
Gently fold in wet mixture and stir until well combined. Next stir in chocolate chunks, reserving a few tablespoons.
Spread batter evenly into prepared pan and sprinkle remaining chocolate chunks on top. Bake for 18-25 minutes or until toothpick comes out clean. Once done baking, transfer pan to a wire rack to cool for 20 minutes before cutting into 12 bars.
To make the chocolate drizzle: Add chocolate chips and coconut oil to a small saucepan and place over low heat. Stir frequently until melted then drizzle over bars.
To make vegan: Instead eggs, replace with flax eggs. Also make sure to use a vegan chocolate bar.
I often use Trader Joe's Cocoa powder, but Ghriradelli's Unsweetened Cocoa powder is another favorite. Another favorite is Dagoba's organic cacao powder. If you use cacao powder, only use 1/3 cup.