Prep the pan: Heat oven to 350°F (175°C). Line a 12-cup muffin tin with liners and lightly mist with oil.
Whisk dry ingredients: In a large bowl, whisk gluten free flour, almond flour, baking powder, baking soda, salt, cinnamon, and nutmeg.
Mix wet ingredients: In a separate bowl, whisk eggs, brown sugar, granulated sugar, oil, applesauce, vanilla, and buttermilk until smooth.
Combine: Pour wet into dry and stir with a spatula until just combined.
The batter should be thick but scoopable.
Fold in carrots: Gently stir in grated carrots and any optional add-ins. Do not overmix.
Fill and rest: Divide batter evenly among cups (about 3/4 full). Let the filled tray sit for 5 minutes to hydrate the flours.
Bake: Bake 18–22 minutes until tops spring back and a tester comes out with a few moist crumbs.
Cool: Rest in the pan 5 minutes, then transfer to a rack to cool completely.
This sets the crumb and keeps them tender.