Preheat and prep: Heat your oven to 400°F (200°C). Line a 12-cup muffin tin with liners or lightly grease.
Mix dry ingredients: In a large bowl, whisk together the Kamut flour, all-purpose flour, baking powder, baking soda, and salt until well combined.
Whisk wet ingredients: In a separate bowl, whisk the granulated sugar, brown sugar, eggs, buttermilk, oil, and vanilla until smooth and slightly frothy.
Combine: Pour the wet mixture into the dry ingredients.
Stir gently with a spatula until just combined. A few streaks of flour are okay.
Add chips: Fold in the chocolate chips (and nuts, if using) with minimal stirring. Overmixing makes muffins tough.
Fill the tin: Divide the batter evenly among the 12 cups, filling them about 3/4 full.
Sprinkle tops with a pinch of turbinado sugar if you like a crunch.
Bake hot, then lower: Bake at 400°F (200°C) for 5 minutes to help lift the tops. Without opening the oven, reduce heat to 350°F (175°C) and bake another 12–15 minutes, until the centers spring back and a tester comes out with a few moist crumbs.
Cool: Let the muffins rest in the pan for 5 minutes, then transfer to a rack to cool. Enjoy warm while the chocolate is melty.