Preheat the oven to 350 degrees F (175 degrees C). Grease and flour a 6-cavity mini loaf tray.

Mix carrots, flour, sugar, walnuts, oil, eggs, baking soda, baking powder, cinnamon, and salt in a large bowl until combined. Pour batter into the prepared tray, filling each loaf cavity 3/4 full.

Bake in the preheated oven until a toothpick inserted into the center comes out clean, 25 to 30 minutes. Cool in the pan for 5 to 10 minutes, then transfer loaves to a wire rack to finish cooling.