Preheat oven to 350℉ (180℃)
Prepare 2 baking sheets by lining with parchment paper or silicone mats.
In a medium bowl, whisk together flour, cocoa, salt and baking powder. Set aside for later. Optional: sift ingredients together to remove any lumps in the cocoa powder and flour.
1 ¼ Cups Gluten-free flour, ½ Cup Dutch Processed Cocoa Powder, 1 teaspoon Salt, 2 teaspoons Baking Powder
Melt chocolate and coconut oil gradually over a pot of simmering water or in a microwave (note: the coconut oil is optional). Cool slightly and set aside for later.
1 ¼ Cup Chocolate Chips, 1 Tablespoon Coconut Oil
Using an electric mixer with the paddle attachment, begin mixing together the butter and granulated sugar until light and fluffy (2 - 4 minutes on medium speed). Scrape down sides of bowl as needed.
8 Tablespoons Unsalted Butter, 1 ¼ Cups Granulated Sugar
Add the eggs to the mixing bowl one at a time, mixing well after each addition. Scrape down the sides of the bowl as needed to ensure everything is fully combined.
2 Large Eggs
Add melted chocolate to the mixing bowl and mix on medium speed, scraping down the sides of the bowl occasionally, until the chocolate is fully blended in.
Add milk to the mixing bowl. Mix on low speed until combined.
⅓ Cup Whole Milk
Add the flour mixture and mix on low speed just until combined. Be careful not to overmix, as this can make the cookies tough.
Stir in walnuts by hand.
½ Cup Walnuts
Scoop the dough onto the parchment-lined baking sheets using a cookie scooper (approximately 2 tablespoons per cookie). Leave approximately 2 inches of space between each cookie.
Bake cookies for 9 - 10 minutes, or until tops and edges of cookies are browning.
Let cookies cool on the baking sheets for 5 to 10 minutes, then transfer to a wire rack to cool completely.