Preheat the oven to 350 degrees. Grease a loaf pan with non-stick cooking spray and set aside.
Chop the lavender finely and whisk it together with the flour, salt, and baking powder in a medium bowl.
In a small bowl, mix the lemon juice and zest together.
In a mixing bowl, cream butter and sugar together until light and fully, 2 minutes. Add eggs, one at a time, and beat on medium after each addition, until eggs are blended in.
Gradually add the flour mixture, beating until incorporated. Then, add the lemon juice and zest.
Pour batter into prepared pan and bake 50-55 minutes, or until a tester comes out clean from the center of the loaf.
Allow loaf to cool, then remove from pan. Sift powdered sugar on top of the loaf and slice.