Preheat the oven to 350°F. Grease and flour a 9-inch loaf pan.
In a medium bowl, whisk together the flour, baking soda, baking powder, salt and cinnamon. Set aside.
In a large bowl, whisk together the sugars, eggs, oil and vanilla until blended. Add the dry ingredients, stirring until just blended. Fold in the rhubarb.
Pour the batter into the prepared pan. Bake for 55 to 65 minutes, or until a toothpick inserted into the center comes out clean. Cool in the pan for 10 minutes before turning out onto a wire rack to cool completely.
To make the glaze, mix together the confectioners sugar and milk. Drizzle over cooled loaf.
Interesting Facts
Rhubarb is a vegetable, not a fruit.
Rhubarb is one of the earliest plants to be harvested from the garden in the spring.