Preparation

Make the bread

• Position a rack in the lower third of the oven and heat the oven to 350°F. Butter and then flour the bottom and sides of a 6-cup (8-1/2 x 4-1/2-inch or 9 x 5-inch) loaf pan, tapping out any excess flour.
• In a large bowl, combine the flour, sugar, poppy seeds, lavender, baking powder, and salt. Whisk until well blended.
• In a medium bowl, combine the milk, eggs, lemon zest, and vanilla. Whisk until blended. Pour the wet ingredients over the dry ingredients. Add the melted butter. Using a silicone spatula, gently fold until blended.
• Scrape the batter into the prepared pan and spread evenly.
• Bake, rotating halfway through, until the top is golden and a wooden skewer or toothpick inserted in the center comes out clean, 50 to 55 minutes.
• Let cool in the pan on a rack for 30 minutes. Invert the bread and remove the pan, turn the bread right side up, and let cool completely.

Glaze the bread

• In a small bowl, stir the confectioners’ sugar and the lemon juice until smooth, adding more juice, 1 tsp. at a time, until the glaze is just pourable. Drizzle the bread with the glaze and let it set for 30 minutes. Store, covered, at room temperature for up to 2 days.