Preheat the oven to 350°F. Butter and flour a 9x5x 4-inch loaf pan or spray with baking spray. Set aside. (Alternately use two 8x4 inch loaf pans and divide the batter)
In a large bowl use a whisk to sift together the flour, sugar, baking powder, salt, and baking soda.
In a separate medium bowl whisk together the oil, butter, yogurt, eggs, zest, juice and poppy seeds.
Add the wet to the dry ingredients and mix by hand until fully combined. Pour the batter evenly into the loaf pan.
Bake for 1 hour or until a toothpick inserted into the center comes back clean. Cool in the pan for 15 minutes then remove to a cooling rack to cool completely.
Once cooled, in a small bowl whisk together the powdered sugar and lemon juice. Drizzle over the loaf. Garnish with additional lemon zest, if desired.
Notes
Please note: The loaf pan I used for this recipe is larger than a standard pan. If you don't have one, divide the batter between two 8 x 4 inch loaf pans or you could bake it in a 9 or 10 inch springform pan. You could also bake this in a standard size Bundt pan. Don't guess at the size, measure to be sure.
When changing the pan shape, the baking time may also need to be adjusted. Always bake this lemon poppy seed bread or any sweet bread, until the center springs back when gently tapped or until a toothpick or cake tester inserted into the center comes back clean.