Preheat your oven to 375F degrees.

In a blender or food processor, process the oats until they are the same consistency as flour. Set aside 2 teaspoons of oat flour.

In a large mixing bowl, stir together the remaining oat flour, baking powder, baking soda, and salt.

In a medium mixing bowl, whisk together the eggs, buttermilk, safflower oil, honey and lemon juice.

Stir the wet ingredients into the dry ingredients just until combined.

Toss frozen blueberries with the reserved 2 teaspoons oat flour until coated.

Gently stir the blueberries, walnuts, rosemary and lemon zest into the batter.

Line your 8x4-inch loaf pan with parchment paper.

Pour batter into pan and spread evenly. Sprinkle a few whole rolled oats over the top, if desired.

Bake for 65 to 70 minutes, or until a toothpick inserted in the center comes out clean.

Remove pan from oven and cool on wire rack for 10 minutes.

Remove bread from pan and cool completely on wire rack.