Preheat your oven to 350°F (175°C). Grease a muffin tin or line with paper liners.
In a large bowl, whisk together the flour, sugar, baking powder, and salt until well combined.
In a separate bowl, whisk together the buttermilk, vegetable oil, and egg until smooth.
Pour the wet ingredients into the dry ingredients and stir gently until just combined. Do not overmix - a few lumps are perfectly fine.
Gently fold in the dried culinary lavender and fresh blueberries until evenly distributed throughout the batter.
Spoon the batter into the prepared tin, filling each cavity about two-thirds full.