Preheat your oven to 325°F (170°C). Line a standard 8.5 x 4.5-inch (or 9x5-inch) loaf pan with parchment paper, leaving a bit of overhang on the sides for easy lifting.
Grate your carrots using the medium setting on a box grater. They don't need to be super fine—a little texture is exactly what we want.
In a large mixing bowl, add the grated carrots, olive oil, eggs, packed brown sugar, ground cinnamon, vanilla extract, self-rising flour, and baking powder.
Using a hand whisk or an electric hand mixer, whisk the mixture just until no lumps of dry flour remain.
Pour the batter into your prepared loaf pan. Bake for at least 1 hour.
Remove from the oven and let it sit in the pan for a few minutes. Carefully lift the cake out using the parchment paper edges and transfer it to a cooling rack.
While the cake cools, whisk together the powdered sugar, pure maple syrup, milk, and vanilla extract in a small bowl until completely smooth. If it's too thick, add a tiny splash of milk; if it's too thin, add a tablespoon more of powdered sugar.
Drizzle the maple glaze generously over the cooled loaf. Slice it up and enjoy!