Preheat oven to 350°F.
Grease a loaf pan, set aside.
In a medium bowl, whisk together flour, baking powder, baking soda and salt. Set aside.
In a large bowl, whisk together sugar, oil, egg, vanilla extract, lemon zest and lemon juice. Stir in flour mixture, alternating with buttermilk. Fold in dried lemon peel and poppyseeds.
Pour batter into prepared loaf pan.
Bake for 45 minutes, or until lightly browned and a toothpick inserted into the center comes out clean. Let rest for 5 minutes in loaf pan before transferring to a cooling rack.
In a small bowl whisk together lemon juice, lemon zest and powdered sugar until of drizzle consistency. Stir in reserved candied diced lemon peel. Drizzle over bread. Allow to cool.