Preheat the oven to 350°F (175°C). Grease a 9x5-inch loaf pan or line it with parchment for easy removal.

In a large bowl, whisk together the flour, sugar, dried lavender, baking powder, baking soda, and salt until evenly distributed. Break up any lavender clusters with your fingers or a fork.

In a second bowl, beat the softened butter until smooth. Add the buttermilk, eggs, and vanilla, and whisk until blended and slightly emulsified.

Pour the wet mixture into the dry ingredients. Fold with a spatula or wooden spoon just until there are no dry streaks — a few small lumps are fine. Overmixing will lead to a tougher crumb.

Scrape the batter into the prepared loaf pan and smooth the top with a spatula. Tap the pan gently on the counter to settle the batter and remove large air pockets.

Bake for 50–60 minutes. Start checking at 50 minutes: insert a toothpick into the center. It should come out clean or with a few moist crumbs clinging. If the top browns too quickly, tent with foil.

Cool the loaf in the pan for 10 minutes, then run a knife around the edges and transfer to a wire rack to cool completely before slicing. Serving too warm can make the slices crumbly.