Prep the oven and pan.
Heat your oven to 350°F (180°C). Line a 9 x 5-inch (23 x 13 cm) loaf pan with parchment, leaving a little overhang for easy lifting. Lightly grease if needed.

Make oat flour.
Add the rolled oats (2 cups / 180 g) to a blender or food processor and blend until they look like a coarse flour—about 30–60 seconds. A few slightly larger flecks are fine.

Mix the batter.
In a large bowl, whisk together the eggs, yogurt, honey or maple syrup, orange juice, and orange zest until smooth. Stir in the baking powder, cinnamon, and optional pinch of salt.

Add oats and carrots.
Stir in the blended oat flour, then fold in the finely grated carrots. The batter will be thick, like a sturdy muffin batter.

Rest briefly (helps texture).
Let the batter sit for 5 minutes so the oats can hydrate a bit. This small pause helps the loaf bake up more evenly and slice cleaner.

Bake.
Spoon the batter into the prepared pan and smooth the top. Bake for 40–45 minutes, until the top looks set and a skewer inserted in the center comes out with only a few moist crumbs (not wet batter). The loaf should smell warmly of orange and cinnamon.

Cool before slicing.
Cool in the pan for 15 minutes, then lift out using the parchment and cool on a rack until barely warm or fully cool. Slicing too hot can make it seem gummy inside.