Line a standard muffin tin with 12 muffin liners and set aside. Wait to preheat the oven until the muffin batter is resting in the refrigerator.

Begin by melting the butter in a small microwave-safe bowl. Since it's only a small amount, this should only take 30-60 seconds. Combine the melted butter with the vegetable oil. Then add the cocoa powder and whisk together until smooth. Allow it to sit while you prepare the rest of the gluten-free muffin batter.

In a small bowl whisk or sift together the gluten-free multi purpose flour blend, baking soda, baking powder, instant espresso and kosher salt. Set aside.

In a large bowl, combine the brown sugar, granulated sugar, vanilla extract and room temperature large eggs. Whisk together.

Add the gluten-free sourdough discard and buttermilk to the mix once the egg and sugar are combined. Whisk together.

Whisk the bloomed cocoa powder into the mixture followed by the dry ingredients. Ensure the dry ingredient and the wet ingredients are fully combined. You may need to switch from a whisk to a flexible spatula making sure there are no pockets of the flour mixture hiding.

With a flexible rubber spatula fold the chocolate chips into the chocolate muffin batter.

Retrieve the prepared muffin pan and divide the batter between the papers with the large cookie scoop. I fill mine almost to the rim. Depending on your scooping and the size of your paper liners, this recipe should yield 12-14 gluten-free muffins.

Top each muffin with additional chocolate chunks if you like.

Place the gluten-free sourdough chocolate muffins in the refrigerator while your oven preheats to 450F. Allowing the batter to rest, even for 15-30 minutes, will help hydrate the flour, building a better crumb. Also, cold muffin batter will rise higher!

When ready to bake the gluten-free chocolate muffins, place them in the fully preheated oven and bake them at 450F for 7 minutes, then reduce the oven temperature to 350F without opening the oven door. Bake the muffins until they are golden brown, around 15-17 minutes.

The muffins are done when until they are firm to touch, and a toothpick inserted in the center comes out clean. Make sure not to overbake them. That will cause them to dry out. Baking times depend on how many muffins you divide the batter into and your oven. Smaller Muffins bake faster, while larger muffins take longer to bake.

Allow the gluten-free muffins to cool in the pan for 5-10 minutes before transferring them to a wire rack. I remove them from the muffin pan with a spoon or a butter knife.