If you need to cook the quinoa, cook it now following package directions and cool it so it is tender but not mushy; grains should be separate. Preheat the oven to 350°F and line a standard 12-cup muffin tin with paper liners or lightly grease it.
In a large bowl, whisk together the cooled cooked quinoa, white whole wheat flour, packed dark brown sugar, ground cinnamon, ground ginger, baking powder, and kosher salt until evenly combined.
In a small bowl or large measuring cup, beat the egg, then whisk in the 1/2 cup plus 2 tablespoons low-fat buttermilk, Greek yogurt, canola oil, and vanilla extract until smooth.
Add the wet mixture to the dry quinoa mixture and stir gently by hand just until combined; do not overmix.
Fold in the grated carrots and the 1/2 cup of chosen mix-ins until evenly distributed.
Divide the batter evenly among the 12 muffin cups.
Bake for 25 to 28 minutes, or until a toothpick inserted into the center of a muffin comes out clean.
Let the pan rest on a wire rack for 5 minutes, then remove the muffins from the tin and cool completely on the rack before serving.
